The principal issues raised on this appeal from a conviction for second degree murder and carrying a dangerous weapon relate to appellant’s defense of insanity. After the case was argued to a division of the court, the court sua sponte ordered rehearing en banc. We identified our intention to reconsider the appropriate standard for the insanity defense, authorized counsel to file supplemental briefs, invited the Public Defenders’ Service “to submit an additional brief on behalf of the appellant,” and appointed William H. Dempsey, Jr., Esq., as amicus curiae, without instruction as to result or theory, “to research the authorities on the issue of criminal responsibility,” to advise the court thereon and to present oral argument. We advised a number of organizations of our action, and invited briefs amicus curiae. Subsequently we directed the Clerk to notify all concerned of questions the court requested be discussed (Appendix A).
In the course of our reconsideration of the rule governing the insanity defense, we have studied the opinions of other courts, particularly but not exelusively the opinions of the other Federal circuits, and the views of the many scholars who have thoughtfully pondered the underlying issues. Our file includes presentations of counsel, both Government lawyers and counsel appointed to represent defendant, and submissions of those who have responded to the invitation to comment as amicus curiae on a considerable number of inter-related matters.
We have stretched our canvas wide; and the focal point of the landscape before us is the formulation of the American Law Institute. The ALI’s primary provision is stated thus in its Model Penal Code, see § 4.01(1).
Section b.01 Mental Disease or Defect Excluding Responsibility.
(1) A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality [wrongfulness] ^of his conduct or to conform his conduct to the requirements of the law.
We have decided to adopt the ALI rule as the doctrine excluding responsibility for mental disease or defect, for application prospectively to trials begun after this date.
The interest of justice that has called us to this labor bids us set forth comments in which we review the matters we concluded were of primary consequence — though we cannot practicably re-traverse all the ground covered in our reflection. These comments also contain features of the rule in which we, like other courts, have recorded our adjustments of the rule and understandings concerning its application that are stated as part of the adoption of the rule, to improve its capacity to further its underlying objectives. We highlight, as most notable of these, our decision to retain the definition of “mental illness or defect” that we evolved in our 1962 McDonald1 opinion en banc. Others are prompted by the submissions which rais*974ed, as points of objection to the ALI rule, matters that we think can be fairly taken into account by clarifying comments. For the assistance of the reader we insert at this point a Table of Contents identifying the topics discussed in this opinion.
TABLE OF CONTENTS
A. The Trial Record............ 974
B. Prior Developments of the Insanity Defense in this Jurisdiction ..................... 975
C. Insanity Rule in Other Circuits ....................... 978
D. Comments Concerning Reason for Adoption of ALI Rule and Scope of Rule as Adopted by This Court.................. 981
1. Need to depart from “productivity” formulation and undue dominance by experts ......t,............ 981
2. Retention of McDonald definition of “mental disease or defect”............... 983
3. Interest of uniformity of judicial approach and vocabulary, with room for variations and adjustments .... 984
4. Consideration and rejection of other suggestions...... 985
a. Proposal to abolish insanity defense......... 985
b. Proposal for defense if mental disease impairs capacity to such an extent that defendant “cannot justly be held responsible.” ............ 986
5. ALI rule is contemplated as improving the process of adjudication, not as affecting number of insanity acquittals ..................... 989
6. Elements of the ALI rule adopted by this court..... 990
a. Intermesh of components 991
b. The “result” of the mental disease............ 991
e. At the time of the conduct ................. 991
d. Capacity to appreciate wrongfulness of his conduct ................. 991
e. Caveat paragraph...... 992
f. Broad presentation to the jury.................. 994
E. Inter-related Doctrines and Implementing Instructions ...... 995
1. Suggested instruction..... 995
Burden of Proof......... 996
2. The “Lyles” instruction— as to effect of verdict of not guilty by reason of insanity ...................... 996
3. Mental condition, though insufficient to exonerate, may be relevant to specific mental element of certain crimes or degrees of crime....... 998
F. Disposition of the Case.......1003
1. Issue of Causality Testimony ......................1003
2. Prosecutor’s conduct......1003
3. Remand.................1004
G. Supplement to Clarify Matters Discussed in Separate Opinion. .1005
Appendix A.....................1007
Appendix B.....................1008
A. The Trial Record
Passing by various minor disagreements among the witnesses, the record permits us to reconstruct the events of September 8, 1967, as follows: After a morning and afternoon of wine-drinking, appellant Archie W. Brawner, Jr. and his uncle Aaron Ross, went to a party at the home of three acquaintances. During the evening, several fights broke out. In one of them, Brawner’s jaw was injured when he was struck or pushed to the ground. The time of the fight was approximately 10:30 p.m. After the fight, Brawner left the party. He told Mr. Ross that some boys had jumped him. Mr. Ross testified that Brawner “looked like he was out of his mind”. Other witnesses who saw him after the *975fight testified that Brawner’s mouth was bleeding and that his speech was unclear (but the same witness added, “I heard every word he said”); that he was staggering and angry; and that he pounded on a mailbox with his fist. One witness testified that Brawner said, “[I’m] going to get my boys” and come back, and that “someone is going to die tonight.”
Half an hour later, at about eleven p. m., Brawner was on his way back to the party with a- gun. One witness testified that Brawner said he was going up there to kill his attackers or be killed.
Upon his arrival at the address, Brawner fired a shot into the ground and entered the building. He proceeded to the apartment where the party was in progress and fired five shots through the closed metal hallway door. Two of the shots struck Billy Ford, killing him. Brawner was arrested a few minutes later, several blocks away. The arresting officer testified that Brawner appeared normal, and did not appear to be drunk, that he spoke clearly, and had no odor of alcohol about him.
After the Government had presented the evidence of its non-expert witnesses, the trial judge ruled that there was insufficient evidence on “deliberation” to go to the jury: accordingly, a verdict of acquittal was directed on first degree murder.
The expert witnesses, called by both defense and prosecution, all agreed that Brawner was suffering from an abnormality of a psychiatric or neurological nature. The medical labels were variously given as “epileptic personality disorder,” “psychologic brain syndrome associated with a convulsive disorder,” “personality disorder associated with epilepsy,” or, more simply, “an explosive personality.” There was no disagreement that the epileptic condition would be exacerbated by alcohol, leading to more frequent episodes and episodes of greater intensity, and would also be exacerbated by a physical blow to the head. The experts agreed that epilepsy per se is not a mental disease or defect, but a neurological disease which is often associated with a mental disease or defect. They further agreed that Brawner had a mental, as well as a neurological, disease.
Where the experts disagreed was on the part which that mental disease or defect played in the murder of Billy Ford. The position of the witnesses called by the Government is that Brawner’s behavior on the night of September 8 was not consistent with an epileptic seizure, and was not suggestive of an explosive reaction in the context of a psychiatric disorder. In the words of Dr. Platkin of St. Elizabeths Hospital, “He was just mad.”
The experts called by the defense maintained the contrary conclusion. Thus, Dr. Eugene Stanmeyer, a psychologist at St. Elizabeths, was asked on direct by counsel for defense, whether, assuming accused did commit the act which occurred, there was a causal relationship between the assumed act and his mental abnormality. Dr. Stanmeyer replied in the affirmative, that there was a cause and effect relationship.
Later, the prosecutor asked the Government’s first expert witness Dr. Weickhardt: “Did you . . . come to any opinion concerning whether or not the crimes in this case were causally related to the mental illness which you diagnosed?” An objection to the form of the question was overruled. The witness then set forth that in his opinion there was no causal relationship between the mental disorder and the alleged offenses. Brawner claims that the trial court erred when it permitted a prosecution expert to testify in this manner. He relies on our opinion in Washington v. United States, 129 U.S.App.D.C. 29, 390 F.2d 444 (1967).
B. Prior Developments of the Insanity ) Defense in this Jurisdiction
History looms large in obtaining a sound perspective for a subject like this one. But the eases are numerous. And since our current mission is to illuminate the present, rather than to linger over *976the past, it suffices for our purposes to review a handful of our opinions on the insanity defense.
1. The landmark opinion was written by Judge Bazelon in Durham v. United States, 94 U.S.App.D.C. 228, 214 F.2d 862 (1954). Prior to Durham, the law of the District of Columbia was established by United States v. Lee, 15 D.C. (4 Mackey) 489, 496 (1886) and Smith v. United States, 59 App.D.C. 144, 36 F.2d 548 (1929), which, taken together, stated a traditional test of insanity, in terms of right and wrong2 and irresistible impulse.3 Durham adopted the “product rule,” pioneered in State v. Pike, 49 N. H. 399, 402 (1869-70), and exculpated from criminal responsibility those whose forbidden acts were the product of a mental disease or defect.
New cases have evoked as much comment as Durham. It has sparked widespread interest in the legal-judicial community and focused attention on the profound problems involved in defining legal responsibility in case of mental illness. It has been hailed as a guide to the difficult and problem-laden intersection of law and psychiatry, ethics and science. It has been scored as an unwarranted loophole through which the cunning criminal might escape from the penalty of the law. We view it more modestly, as the court’s effort, designed in the immemorial manner of the case method that has built the common law, to alleviate two serious problems with the previous rule.
The first of these was a problem of language which raised an important symbolic issue in the law. We felt that the language of the old right-wrong/irresistible impulse rule for insanity was antiquated, no longer reflecting the community’s judgment as to who ought to be held criminally liable for socially destructive acts. We considered the rule as restated to have more fruitful, accurate and considered reflection of the sensibilities of the community as revised and expanded in the light of continued study of abnormal human behavior.
The second vexing problem that Durham was designed to reach related to the concern of the psychiatrists called as expert witnesses for their special knowledge of the problem of insanity, who often and typically felt that they were obliged to reach outside of their professional expertise when they were asked, under the traditional insanity rule established in 1843 by M’Naghten’s Case,4 whether the defendant knew right from wrong. They further felt that the narrowness of the traditional test, which framed the issue of responsibility solely in terms of cognitive impairment, made it impossible to convey to the judge and jury the full range of information material to an assessment of defendant’s responsibility.
2. Discerning scholarship now available asserts that the experts’ fears and concerns reflected a misapprehension as to the impact of the traditional standard in terms of excluding relevant evidence.
Wigmore states the rule to be that when insanity is in issue, “any and all conduct of the person is admissible in evidence.” And the cases support Wigmore’s view. The almost unvarying policy of the courts has been to admit any evidence of abberational behavior so long as it is probative of the *977defendant’s mental condition, without regard to the supposed restrictions of the test used to define insanity for the jury.5
Moreover if the term “know” in the traditional test of “know right from wrong” is taken as denoting affective knowledge, rather than merely cognitive knowledge, it yields a rule of greater flexibility than was widely supposed to exist. Livermore and Meehl, The Virtues of M’Naghten, 51 Minn.L.Rev. 789, 800-08 (1967).
We need not occupy ourselves here and now with the question whether, and to what extent, the M’Naghten rule, ameliorated by the irresistible impulse doctrine, is susceptible of application to include medical insights and information as justice requires. In any event, the experts felt hemmed in by the traditional test; they felt that they could not give the jury and judge the necessary information in response to the questions which the traditional test posed, see 37 F.R.D. 365, 387 (1964).
The rule as reformulated in Durham permitted medical experts to testify on medical matters properly put before the jury for its consideration, and to do so without the confusion that many, perhaps most, experts experienced from testimony structured under the M’Naghten rule. That was a positive contribution to jurisprudence — and one that was retained when the American Law Institute undertook to analyze the problem and proposed a different formulation.
3. A difficulty arose under the Durham rule in application. The rule was devised to facilitate the giving of testimony by medical experts in the context of a legal rule, with the jury called upon to reach a composite conclusion that had medical, legal and moral components.6 However the pristine statement of the Durham rule opened the door to “trial by label.” Durham did distinguish between “disease,” as used “in the sense of a condition which is considered capable of either improving or deteriorating,” and “defect,” as referring to a condition not capable of such change “and which may be either congenital or the result of injury, or the residual effect of a physical or mental disease.” 94 U.S.App.D.C. at 241, 214 F.2d at 875. But the court failed to explicate what abnormality of *978mind was an essential ingredient of these concepts. In the absence of a definition of “mental disease or defect,” medical experts attached to them the meanings which would naturally occur to them — • medical meanings — and gave testimony accordingly. The problem was dramatically highlighted by the weekend flip flop case, In re Rosenfield, 157 F.Supp. 18 (D.D.C.1957). The petitioner was described as a sociopath. A St. Elizabeths psychiatrist testified that a person with a sociopathic personality was not suffering from a mental disease. That was Friday afternoon. On Monday morning, through a policy change at St. Elizabeths Hospital, it was determined as an administrative matter that the state of a psychopathic or sociopathic personality did constitute a mental disease.7
The concern that medical terminology not control legal outcomes culminated in McDonald v. United States, 114 U.S.App.D.C. 120, 312 F.2d 847, 851 (en banc, 1962), where this court recognized that the term, mental disease or defect, has various meanings, depending upon how and why it is used, and by whom. Mental disease means one thing to a physician bent on treatment, but something different, if somewhat overlapping, to a court of law. We provided a legal definition of mental disease or defect, and held that it included “any abnormal condition of the mind which substantially affects mental or emotional processes and substantially impairs behavior controls.” (312 F.2d at 851). “Thus the jury would consider testimony concerning the development, adaptation and functioning of these processes and controls.” Id.
While the McDonald standard of mental disease was not without an attribute of circularity, it was useful in the administration of justice because it made plain that clinical and legal definitions of mental disease were distinct, and it helped the jury to sort out its complex task and to focus on the matters given it to decide.
4. The Durham rule- also required explication along other lines, notably the resolution o,f the ambiguity inherent in the formulation concerning actions that were the “product” of mental illness. It was supplemented in Carter v. United States, 102 U.S.App.D.C. 227 at 234, 235, 252 F.2d 608 at 615-616 (1957):
The simple fact that a person has a mental disease or defect is not enough to relieve him of responsibility for a crime. There must be a relationship between the disease and the criminal act; and the relationship must be such as to justify a reasonable inference that the act would not have been committed if the person had not been suffering from the disease.
Thus Carter clarified that the mental illness must not merely have entered into the production of the act, but must have played a necessary role. Carter identified the “product” element of the rule with the “but for” variety of causation.
The pivotal “product” term continued to present problems, principally that it put expert testimony on a faulty footing. Assuming that a mental disease, in the legal sense, had been established, the fate of the defendant came to be determined by what came to be referred to by the legal jargon of “productivity.” On the other hand, it was obviously sensible if not imperative that the experts having pertinent knowledge should speak to the crucial question whether the mental abnormality involved is one associated with aberrant behavior. But since “productivity” was so decisive a factor in the decisional equation, a ruling permitting experts to testify expressly in language of “product” raised in a different context the concern lest the ultimate issue be in fact turned over to the experts rather *979than retained for the jurors representing the community.
The problem was identified by then Circuit Judge Burger in his concurring opinion in Blocker: 8
The hazards in allowing experts to testify in precisely or even substantially the terms of the ultimate issue are apparent. This is a course which, once allowed, risks the danger that lay juroi’S, baffled by the intricacies of expert discourse and unintelligible technical jargon may be tempted to abdicate independent analysis of the facts on which the opinion rests. . .
As early as Carter, we had warned that the function of an expert was to explain the oi'igin, development and manifestations of mental disorders, in terms that would be coherent and meaningful to the jury. “Unexplained medical labels . . . are not enough.” (102 U.S.App.D.C. at 236, 252 F.2d at 617). Even after McDonald, however, we continued to see cases where the testimony of the experts was limited to the use of conclusory labels, without the explication of the underlying analysis. We do not say this was deliberated by the experts. It seems in large measure to have reflected tactical decisions of counsel, and perhaps problems of communications between the disciplines.
It was in this context that the court came to the decision in Washington v. United States, 129 U.S.App.D.C. 29, 390 F.2d 444 (1967), which forbade expei'ts from testifying as to productivity altogether. Chief Judge Bazelon’s opinion illuminates the basis of the ruling, as one intended “to help the psychiatrists understand their role in court, and thus eliminate a fundamental cause of unsatisfactory expert testimony,” namely, the tendency of the expert to use “concepts [which] can become slogans, hiding facts and representing nothing more than the witness’s own conclusion about the defendant’s criminal responsibility.” (at 41, 390 F.2d at 456).
C. Insanity Rule in Other Circuits
The American Law Institute’s Model Penal Code expressed a rule which has become the dominant force in the law pertaining to the defense of insanity. The ALI rule is eclectic in spirit, partaking of the moral focus of M’Naghten, the practical accommodation of the “control rules” (a term more exact and less susceptible of misunderstanding than “irresistible impulse” terminology), and responsive, at the same time, to a relatively modern, forward-looking view of what is encompassed in “knowledge.”
For convenience, we quote again the basic rule propounded by the ALI’s Model Penal Code:
A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of the law.
A subsidiary rule in paragraph (2), stating what has come to be known as the “caveat” paragraph, has had a mixed l'eception in the courts and discussion of that problem will be deferred.
The core rule of the ALI has been adopted, with variations, by all save one of the Federal circuit courts of appeals, and by all that have come to reconsider the doctrine providing exculpation for mental illness. Their opinions have been exceptionally thoughtful and thorough in their expositions of the interests and values protected. United States v. Freeman, 357 F.2d 606 (2d Cir. 1966); United States v. Currens, 290 F.2d 751 (3d Cir. 1961); United States v. Chandler, 393 F.2d 920 (4th Cir. 1968); Blake v. United States, 407 F.2d 908 (5th Cir. 1969); United States v. Smith, 404 F.2d 720 (6th Cir. 1968); United States v. Shapiro, 383 F.2d 680 (7th Cir. 1967); Pope v. United States, 372 F.2d 710 (8th Cir. 1967); Wade v. United States, 426 F.2d 64 (9th Cir. 1970); Wion v. United States, 325 F.2d 420 (10th Cir. 1963).
*980These opinions show that the ALI rule has proved peculiarly subject to successful adaptation, permitting variations but within a framework of uniformity.
The first was Currens, where Chief Judge Biggs of the Third Circuit defined the test:
The jury must be satisfied that at the time of committing the prohibited act the defendant, as a result of mental disease or defect, lacked substantial capacity to conform his conduct to the requirements of the law which he is alleged to have violated. (290 F.2d at 774) (footnote omitted).
This formula is explicitly derived from the ALI rule. (Id. at 774 footnote 32.) It takes an additional step, however, in that it treats cognitive impairments as “surplusage” to a test of criminal responsibility. Ibid. The premise is that an abnormality in the cognitive function is neither sufficient nor necessary. If it does not result in a substantial incapacity of the volitional function, it is not sufficient in law; and a substantial incapacity of the volitional function results in exculpation even though it does not involve the cognitive faculties.
Thus Currens capped the history of the insanity defense — which began with impairment of knowledge and proceeded to impairment of control — by dropping the knowledge feature as merely one aspect of the ultimate control element. Though not without considerable force and logic Currens has not been followed by the other Federal courts, which adhere more closely to the ALI model.
We refer to the other Federal circuits in numerical order. The First Circuit has not spoken. The Second Circuit adopted, the ALI rule in Freeman in terms, believing it to be “sufficiently precise ... to provide the jury with a workable standard,” while “eschew[ing] rigid classification.” 357 F.2d at 623.
The position of the Fourth Circuit was announced by Chief Judge Haynsworth in Chandler:
The American Law Institute’s formulation has achieved wide acceptance. Some Courts of Appeals have adopted it exclusively, another approvingly but not rigidly, still others with prescribed variations which subordinate the cognitive portion of the problem or satisfy semantic preferences. . [I]t is, in our opinion, the preferred formulation. With appropriate balance between cognition and volition, it demands an unrestricted inquiry into the whole personality of a defendant who surmounts the threshold question of doubt of his responsibility. Its verbiage is understandable by psychiatrists; it imposes no limitation upon their testimony, and yet, to a substantial extent, it avoids a diagnostic approach and leaves the jury free to make its findings in terms of a standard which society prescribes and juries may apply. (393 F.2d at 926, footnotes omitted.)
The court, however, “abjure [d] any formalistic approach which might foreclose variation.” (at 927). Thus the court declined to require any exact form of words by way of instructions.
In Blake the Fifth Circuit stressed the value of uniformity. While affirming the utility of variation as a form of social experiment, and noting that variation among the circuits was not inconsiderable, it stated that, at least as within the circuit, uniformity was a preferable value. “We think [the ALI formula] lends itself as a uniform standard.” 407 F.2d at 915.
The Sixth Circuit has been content to leave the precise wording of the jury instructions to the discretion of the trial court, preferring to frame its approach in terms of getting the answers to three irreducible questions: First, was defendant “suffering from a mental illness at the time of the commission of the crime ?” Second, “Was that illness such as to prevent his knowing the wrongfulness of his act?” Third, “Was the mental illness such as to render him substantially incapable of conforming his conduct *981to the requirements of the law he is charged with violating ?” This formulation in Smith, 404 F.2d at 727, is essentially a restatement of the core of the ALI test.
In Shapiro, the Seventh Circuit stated, 383 F.2d at 685, that it preferred the ALI rule to other possible formulae on the ground that it resulted in a charge shorter, simpler, and more congruent to the expert testimony than the charge based on Davis v. United States, 165 U.S. 373, 17 S.Ct. 360, 41 L.Ed. 750 (1897), which was a traditional test and itself based on M’Naghten; it found the ALI test more comprehensible than Durham and more helpful to the jury.
The position of the Eighth Circuit was staked out in Pope by then Circuit Judge Blackmun:
We hold again, and we stress by repetition, that if the trial court freely admits all evidence which appears to be relevant and if the charge appropriately embraces and requires positive conclusions by the jury as to the defendant’s cognition, his volition, and his capacity to control his behavior, and if these three elements of knowledge, will and choice are emphasized in the charge as essential and critical constituents of legal sanity, we shall usually regard the charge as legally sufficient. 372 F.2d at 736 (Italics in original.)
The court said (p. 735) that it would look with approval upon any form of instruction so long as it resulted in presenting the issue to the jury with as much information as possible on cognition, volition, and the capacity to choose.
In Wade, the latest of the Federal opinions, the Ninth Circuit approved the basic ALI rule, though rejecting the “caveat” second paragraph. The court noted that the traditional M’Naghten rule asked the jury to determine the existence of a “perverted and deranged condition of the mental and moral faculties,” while the ALI’s “mental disease or defect” language was preferable, focusing on disabling impairments in terms closer to the kind o.f expert testimony which the jury will hear.
The position of the Tenth Circuit, very near to that of the Eighth, was stated in Wion where Judge Murrah presented, as a “simple test of criminal responsibility,” language that restated the essence of the ALI rule. Noting that the test permitted behavioral scientists latitude to put their professional findings and conclusions before the court he concluded: “This should go far toward bridging the gulf between psychiatry and the law, if indeed, there is one, and it will also give the trial judge a definition which he can articulate to the lay jury.” 325 F.2d at 430.
D. Comments Concerning Reason for Adoption of ALI Rule and Scope of Rule as Adopted By This Court
In the foreglimpse stating that we, had determined to adopt the ALI rule we undertook to set forth comments stating our reasons, and also the adjustments and understandings defining the ALI rule as adopted by this Court. Having paused to study the rulings in the other circuits, we turn to our comments, and to our reflections following the extensive, and intensive, exposure of this court to insanity defense issues.9
1. Need to depart from “product” formulation and undue dominance by experts.
A principal reason for our decision to depart from the Durham, rule is the undesirable characteristic, surviving even the McDonald modification, of undue dominance by the experts giving testimony. The underlying problem was identified, with stress on different *982facets, in the Carter, Blocker (concurring), and Washington opinions. The difficulty is rooted in the circumstance that there is no generally accepted understanding, either in the jury or the community it represents, of the concept requiring that the crime be the “product” of the mental disease.
When the court used the term “product” in Durham it likely assumed that this was a serviceable, and indeed a natural, term for a rule defining criminal responsibility — a legal reciprocal, as it were, for the familiar term “proximate cause,” used to define civil responsibility. But if concepts like “product” are, upon refinement, reasonably understood, or at least appreciated, by judges and lawyers, and perhaps philosophers, difficulties developed when it emerged that the “product" concept did not signify a reasonably identifiable common ground that was also shared by the nonlegal experts,10 and the laymen serving on the jury as the representatives of the community.
The doctrine of criminal responsibility is such that there can be no doubt “of the complicated nature of the decision to be made — intertwining moral, legal, and medical judgments,” see King v. United States, 125 U.S.App.D.C. 318, 324, 372 F.2d 383, 389 (1967) and Durham and other cases cited supra, note 6. Hence, as King and other opinions have noted, jury decisions have been accorded unusual deference even when they have found responsibility in the face of a powerful record, with medical evidence uneontradicted, pointing toward exculpation.11 The “moral” elements of the decision are not defined exclusively by religious considerations but by the totality of underlying conceptions of ethics and justice shared by the community, as expressed by its jury surrogate. The essential feature of a jury “lies in the interposition between the accused and his accuser of the commonsense judgment of a group of laymen, and in the community participation and shared responsibility that results from that group’s determination of guilt or innocence.” Williams v. Florida, 399 U.S. 78, 100, 90 S.Ct. 1893, 1906, 26 L.Ed.2d 446 (1970).
The expert witnesses — psychiatrists and psychologists — are called to adduce relevant information concerning what may for convenience be referred to as the “medical” component of the responsibility issue. But the difficulty — as emphasized in Washington — is that the medical expert comes, by testimony given in terms of a non-medical construct (“product”), to express conclusions that *983in essence embody ethical and legal conclusions. There is, indeed, irony in a situation under which the Durham rule, which was adopted in large part to permit experts to testify in their own terms concerning matters within their domain which the jury should know, resulted in testimony by the experts in terms not their own to reflect unexpressed judgments in a domain that is properly not theirs but the jury’s. The irony is heightened when the jurymen, instructed under the esoteric “product” standard, are influenced significantly by “product” testimony of expert witnesses really reflecting ethical and legal judgments rather than a conclusion within the witnesses’ particular expertise.
It is easier to identify and spotlight the irony than to eradicate the mischief. The objective of Durham is still sound— to put before the jury the information that is within the expert’s domain, to aid the jury in making a broad and comprehensive judgment. But when the instructions and appellate decisions define the “product” inquiry as the ultimate issue, it is like stopping the.tides to try to halt the emergence of this term in the language of those with a central role in the trial — the lawyers who naturally seek to present testimony that will influence the jury who will be charged under the ultimate “product” standard, and the expert witnesses who have an awareness, gained from forensic psychiatry and related disciplines, of the ultimate “product” standard that dominates the proceeding.
The experts have meaningful information to impart, not only on the existence of mental illness or not, but also on its relationship to the incident charged as an offense. In the interest of justice this valued information should be available, and should not be lost or blocked by requirements that unnaturally restrict communication between the experts and the jury. The more we have pondered the problem the more convinced we have become that the sound solution lies not in further shaping of the Durham product” approach in more refined molds, but in adopting the ALI’s formulation as the linchpin of our jurisprudence. <<
The ALI’s formulation retains the core requirement of a meaningful relationship between the mental illness and the incident charged. The language in the ALI rule is sufficiently in the common ken that its use in the courtroom, or in preparation for trial, permits a reasonable three-way communication — between (a) the law-trained, judges and lawyers; (b) the experts and (c) the jurymen— without insisting on a vocabulary that is either stilted or stultified, or conducive to a testimonial mystique permitting expert dominance and encroachment on the jury’s function. There is no indication in the available literature that any such untoward development has attended the reasonably widespread adoption of the ALI rule in the Federal courts and a substantial number of state courts.
2. Retention of McDonald definition of “mental disease or defect."
Our ruling today includes our decision that in the ALI rule as adopted by this court the term “mental disease or defect” includes the definition of that term provided in our 1962 en banc McDonald opinion, as follows:
[A] mental disease or defect includes any abnormal condition of the mind which substantially affects mental or emotional processes and substantially impairs behavior controls.
McDonald v. United States, 114 U.S.App.D.C. at 124, 312 F.2d at 851.
We take this action in response to the problem, identified by amicus comments of Mr. Dempsey and the D.C. Bar Association, that the ALI’s rule, lacking definition of “mental disease or defect,” contains an inherent ambiguity. These comments consider this a reason for avoiding the ALI rule. We find more merit in the suggestion of Mr. Flynn, counsel appointed to represent appellant, *984that the McDonald definition be engrafted on to the ALI rule.12
In our further discussion of ALI and McDonald, we shall sometimes refer to “mental disease” as the core concept, without specifically referring to the possibility of exculpation by reason of a non-altering “mental defect.”
The McDonald rule has helped accomplish the objective of securing expert testimony needed on the subject of mental illness, while guarding against the undue dominance of expert testimony or specialized labels. It has thus permitted the kind of communication without encroachment, as between experts and juries, that has prompted us to adopt the ALI rule, and hence will help us realize our objective. This advantage overrides the surface disadvantage of any clumsiness in the blending of the McDonald component, defining mental disease, with the rest of the ALI rule, a matter we discuss further below.
3. Interest of uniformity of judicial approach and vocabulary, with room for variations and adjustments
Adoption of the ALI rule furthers uniformity of judicial approach — a feature eminently desirable, not as a mere glow of “togetherness,” but as an appreciation of the need and value of judicial communication. In all likelihood, this court’s approach under Durham, at least since McDonald, has differed from that of other courts in vocabulary more than substance. Uniformity of vocabulary has an important value, however, as is evidenced from the familiar experience of meanings that “get lost in translation.” No one court can amass all the experience pertinent to the judicial administration of the insanity defense. It is helpful for courts to be able to learn from each other without any blockage due to jargon. It is an impressive virtue of the common law, that its distinctive reliance on judicial decisions to establish the corpus of the law furthers a multiparty conversation between men who have studied a problem in various places at various times.
The value of uniformity of central approach is not shattered by the circumstance that in various particulars the different circuits have inserted variations in the ALI rule. Homogeneity does not mean rigidity, and room for local variation is likely a strength, providing a basis for comparison,13 not a weakness. Nor is the strength of essential uniformity undercut by the caution of our appointed amicus that the formulation of the ALI rule provides extremely broad flexibility.14 Flexibility and ductility are inherent in the insanity defense, as in any judicial rule with an extensive range — say, negligence, or proximate cause — and the ALI rule permits appropriate guidance of juries.
In prescribing a departure from Durham we are not unmindful of the concern that a change may generate uncertainties as to corollaries of the change.15 While the courts adopting the ALI rule have stated variations, as we have noted, these were all, broadly, in furtherance of *985one or more of the inter-related goals of the insanity defense:
(a) a broad input of pretinent facts and opinions
(b) enhancing the information, and judgment
(c) of a jury necessarily given latitude in light of its functioning as the representative of the entire community.
We are likewise and for the same objectives defining the ALI rule as adopted by the court, with its contours and corollaries given express statement at the outset so as to minimize uncertainty. We postpone this statement to a subsequent phase of the opinion (see p. 990 et seq.) in order that we may first consider other alternatives, for in some measure our adaptation may obviate or at least blunt objections voiced to the ALI rule.
4. Consideration and rejection of other suggestions
a. Proposal to abolish insanity defense
A number of proposals in the journals recommend that the insanity defense be abolished altogether.16 This is advocated in the amicus brief of the National District Attorneys Association as both desirable and lawful.17 The amicus brief of American Psychiatric Association concludes it would be desirable, with appropriate safeguards, but would require a constitutional amendment. That a constitutional amendment would be required is also the conclusion of others, generally in opposition to the proposal.18
This proposal has been put forward by responsible judges for consideration, with the objective of reserving psychiatric overview for the phase of the criminal process concerned with disposition of the person determined to have been the actor.19 However, we are convinced that the proposal cannot properly be imposed by judicial fiat.
The courts have emphasized over the centuries that “free will” is the postulate of responsibility under our jurisprudence. 4 Blackstone’s Commentaries 27. The concept of “belief in freedom of the human will and a consequent ability and duty of the normal individual to choose between good and evil” is a core concept that is “universal and persistent in mature systems of law.” Morissette v. United States, 342 U.S. 246, 250, 72 S.Ct. 240, 243, 96 L.Ed. 288 (1952). Criminal responsibility is assessed when through “free will” a man elects to do evil. And while, as noted in Morissette, the legislature has dispensed with mental element in some statutory offenses, in furtherance of a paramount need of the community, these instances mark the exception and not the rule, and only in the most limited instances has the mental element been omitted by the legislature as a requisite for an offense that was a crime at common law.
*986The concept of lack of “free will” is both the root of origin of the insanity defense and the line of its growth.20 This cherished principle is not undercut by difficulties, or differences of view, as to how best to express the free will concept in the light of the expansion of medical knowledge. We do not concur in the view of the National District Attorneys Association that the insanity defense should be abandoned judicially, either because it is at too great a variance with popular conceptions of guilt21 or fails “to show proper respect for the personality of the criminal [who] is liable to resent pathology more than punishment.” 22
These concepts may be measured along with other ingredients in a legislative re-examination of settled doctrines of criminal responsibility, root, stock and branch. Such a reassessment, one that seeks to probe and appraise the society’s processes and values, is for the legislative branch, assuming no constitutional bar. The judicial role is limited, in Justice Holmes’s figure, to action that is molecular, with the restraint inherent in taking relatively small steps, leaving to the other branches of government whatever progress must be made with seven-league leaps. Such judicial restraint is particularly necessary when a proposal requires, as a mandatory ingredient, the kind of devotion of resources, personnel and techniques that can be accomplished only through whole-hearted legislative commitment.
To obviate any misunderstanding from our rejection of the recommendation of those proposing judicial abolition of the insanity defense, we expressly commend their emphasis on the need for improvement of dispositional resources and programs. The defense focuses on the kind of impairment that warrants exculpation, and necessarily assigns to the prison walls many men who have serious mental impairments and difficulties. The needs of society — rooted not only in humanity but in practical need for attempting to break the recidivist cycles, and halt the spread of deviant behavior — call for the provision of psychiatrists, psychologists and counselors to help men with these mental afflictions and difficulties, as part of a total effort toward a readjustment that will permit re-integration in society.
b. Proposal for defense if mental disease impairs capacity to such an extent that the defendant cannot “justly be held responsible.”
We have also pondered the suggestion that the jury be instructed that the defendant lacks criminal responsibility if the jury finds that the defendant’s mental disease impairs his capacity or controls to such an extent that he cannot “justly be held responsible.”
This was the view of a British commission,23 adapted and proposed in 1955 by Professor Weehsler, the distinguished Reporter for the ALI’s Model Penal Code, and sustained by some, albeit a minority, of the members of the ALI’s Council.24 In the ALI, the contrary view prevailed because of a concern over presenting to *987the jury questions put primarily in the form of “justice.”
The proposal is not to be condemned out of hand as a suggestion that the jury be informed of an absolute prerogative that it can only exercise by flatly disregarding the applicable rule of law. It is rather a suggestion that the jury be informed of the matters the law contemplates it will take into account in arriving at the community judgment concerning a composite of factors.25
However, there is a substantial concern that an instruction overtly east in terms of “justice” cannot feasibly be restricted to the ambit of what may properly be taken into account but will splash with uneonfinable and malign consequences. The Government cautions that “explicit appeals to ‘justice’ will result in litigation of extraneous issues and will encourage improper arguments to the jury phrased solely in terms of ‘sympathy’ and ‘prejudice.’ ”
Nor is this solely a prosecutor’s concern.
Mr. Flynn, counsel appointed to represent defendant, puts it that even though the jury is applying community concepts of blameworthiness “the jury should not be left at large, or asked to find out for itself what those concepts are.”
The amicus submission of the Public Defender Service argues that it would be beneficial to focus the jury’s attention on the moral and legal questions intertwined in the insanity defense. It expresses concern, however, over a blameworthiness instruction without more, saying (Br. 19) “it may well be that the ‘average’ American condemns the mentally ill.” 26 It would apparently accept an approach not unlike that proposed by the ALI Reporter, under which the justice standard is coupled with a direction to consider the individual’s capacity to control his behavior. Mr. Dempsey’s recommendation is of like import, with some simplification.27 But the problem remains, whether, assuming justice calls for the exculpation and treatment of the mentally ill, that is more likely to be gained from a jury, with “average” notions of mental illness, which is explicitly set at large to convict or acquit persons with impaired mental capacity according to its concept of justice.
The brief of the D.C. Bar Association as amicus submits that with a “justly responsible” formulation the test of insanity “would be largely swallowed up by this consideration.” And it observes that the function of giving to the jury the law to be applied to the facts is not only the duty of the court, see Sparf v. United States, 156 U.S. 51, 102, 15 S.Ct. 273, 39 L.Ed. 343 (1895), but is also “a bedrock right of every citizen” — and, possibly, his “only protection,” citing Justice Story in United States v. Battiste, 2 Sumn. 240, 244, Fed.Cas. No. 14,545 (C.C.D.Mass. 1835).
*988We are impressed by the observation of Professor Abraham S. Goldstein, one of the most careful students of the problem
[The] overly general standard may place too great a burden upon the jury. If the law provides no standard, members of the jury are placed in the difficult position of having to find a man responsible for no other reason than their personal feeling about him. Whether the psyches of individual jurors are strong enough to make that decision, or whether the “law” should put that obligation on them, is open to serious question. It is far easier for them to perform the role assigned to them by legislature and courts if they know- — or are able to rationalize — that their verdicts are “required” by law.28
Professor Goldstein was referring to the broad “justice” standard recommended by the Royal Commission. But the problems remain acute even with the modifications in the proposal of the ALI Reporter, for that still leads to “justly responsible” as the ultimate and critical term.
There may be a tug of appeal in the suggestion that law is a means to justice and the jury is an appropriate tribunal to ascertain justice. This is a simplistic syllogism that harbors the logical fallacy of equivocation, and fails to take account of the different facets and dimensions of the concept of justice. We must not be beguiled by a play on words. The thrust of a rule that in essence invites the jury to ponder the evidence on impairment of defendant’s capacity and appreciation, and then do what to them seems just, is to focus on what seems “just” as to the particular individual. Under the eenturies-long pull of the Judeo-Christian ethic, this is likely to suggest a call for understanding and forgiveness of those who have committed crimes against society, but plead the influence of passionate and perhaps justified grievances against that society, perhaps grievances not wholly lacking in merit. In the domain of morality and religion, the gears may be governed by the particular instance of the individual seeking salvation. The judgment of a court of law must further justice to the community, and safeguard it against undercutting and evasion from overconcern for the individual. What this reflects is not the rigidity of retributive justice — an eye for an eye — but awareness how justice in the broad may be undermined by an excess of compassion as well as passion. Justice to the community includes penalties needed to cope with disobedience by those capable of control, undergirding a social environment that broadly inhibits behavior destructive of the common good. An open society requires mutual respect and regard, and mutually reinforcing relationships among its citizens, and its ideals of justice must safeguard the vast majority who responsibly shoulder the burdens implicit in its ordered liberty. Still another aspect of justice is the requirement for rules of conduct that establish reasonable generality, neutrality and constancy. Cf. L. Fuller, The Morality of Laws 33-94 (1964). This concept is neither static nor absolute, but it would be sapped by a rule that invites an ad hoc redefinition of the “just” with each new case.
It is the sense of justice propounded by those charged with making and declaring the law — legislatures and courts- — -that lays down the rule that persons without substantial capacity to know or control the act shall be excused. The jury is concerned with applying the community understanding of this broad rule to particular lay and medical facts. Where the matter is unclear it naturally will call on its own sense of justice to help it determine the matter. There is wisdom in the view that a jury generally understands well enough that an instruction composed in flexible terms gives it sufficient latitude so that, without disregarding the instruction, it can provide that application of the instruction which *989harmonizes with its sense of justice.29 The ALI rule generally communicates that meaning. Wade v. United States, supra,, 426 F.2d at 70-71. This is recognized even by those who might prefer a more explicit statement of the matter.30 It is one thing, however, to tolerate and even welcome the jury’s sense of equity as a force that affects its application of instructions which state the legal rules that crystallize the requirements of justice as determined by the lawmakers of the community. It is quite another to set the jury at large, without such crystallization, to evolve its own legal rules and standards of justice. It would likely be counter-productive and contrary to the larger interest of justice to become so explicit — in an effort to hammer the point home to the very occasional jury that would otherwise be too rigid — that one puts serious strains on the normal operation of the system of criminal justice.
Taking all these considerations into account we conclude that the ALI rule as announced is not productive of injustice, and we decline to proclaim the broad “justly responsible” standard.
5. ALI rule is contemplated as improving the process of adjudication, not as affecting number of insanity acquittals
Amicus Dempsey is concerned that a change by this court from Durham-McDonald to ALI will be taken as an indication that this court intends that the number and percentage of insanity acquittals be modified. That is not the intendment of the rule adopted today, nor do we have any basis for forecasting that effect.
a. Statistical data concerning the use of insanity in criminal trials in this jurisdiction were presented in the December 15, 1966, Report of the President’s Commission on Crime in the District of Columbia.31 These data have been up-dated in Mr. Dempsey’s brief, with the aid of data helpfully supplied by the United States Attorney’s office. At least since Durham was modified by McDonald, insanity acquittals have run at about 2% of all cases terminated. In the seven years subsequent to McDonald jury verdicts of not guilty by reason of insanity averaged only 3 per annum.32 In trials by the court, there has been an annual average of about 38 verdicts of not guilty by reason of insanity; these typically are cases where the Government psychiatrists agreed that the crime was the product of mental illness.33 We perceive no basis in these data for any conclusion that the number of percentage of insanity acquittals has been either excessive or inadequate.
We have no way of forecasting what will be the effect on verdicts, of juries or judges, from the reduction in influence of expert testimony on “productivity” *990that reflects judgments outside the domain of.expertise.34 Whatever its effect, we are confident that the rule adopted today provides a sounder relationship in terms of the giving, comprehension and application of expert testimony. Our objective is not to steer the jury's verdict but to enhance its deliberation.35
b. Some judges have viewed the ALI test as going beyond Durham in enlarging the category of persons who may win acquittals.36 The 1966 report of the President’s Crime Commission (supra note 15) apparently concludes that the debate over Durham was stilled by McDonald, and that Durham-McDonald is not significantly different in content from the ALI test. In contrast, Mr. Dempsey is concerned that a person’s ability to control his behavior could be “substantially impaired” by mental condition, thus qualifying the defense under McDonald, while still leaving him with “substantial capacity,” rendering the defense unavailable under the ALI rule. We have no way of knowing whether psychiatrists giving testimony would draw such a distinction, and moreover there would be no difference in result unless one also indulges the assumption, which is dubious, that the jury would reason that the crime may have been the “product” of the mental condition of a man even though he retained substantial capacity.
In the last analysis, however, if there is a case where there would be a difference in result — and it would seem rare —we think the underlying freedom of will conception renders it just to assign responsibility to a person, even though his controls have been impaired, if his •residual controls give him “substantial capacity” both to appreciate the wrongfulness of his conduct and to conform it to the requirement of law. Whether the ALI standard is to be given a narrow or broad conception rests not on abstract analysis 37 but on the application reflecting the underlying sense of responsibility of the jury, as the community’s surrogate.38
6. Elements of the ALI rule adopted by this court
Though it provides a general uniformity, the ALI rule leaves room for variations. Thus, we have added an adjustment in the McDonald definition of mental disease, which we think fully *991compatible with both the spirit and text of the ALI rule. In the interest of good administration, we now undertake to set forth, with such precision as the subject will permit, other elements of the ALI rule as adopted by this court.
The two main components of the rule define (1) mental disease, (2) the consequences thereof that exculpate from responsibility.
a. Intermesh of components
The first component of our rule, derived from McDonald, defines mental disease or defect as an abnormal condition of the mind, and a condition which substantially (a) affects mental or emotional processes and (b) impairs behavioral controls. The second component, derived from the Model Penal Code, tells which defendant with a mental disease lacks criminal responsibility for particular conduct: it is the defendant who, as a result of this mental condition, at the time of such conduct, either (i) lacks substantial capacity to appreciate that his conduct is wrongful, or (ii) lacks substantial capacity to conform his conduct to the law.
The first component establishes eligibility for an instruction concerning the defense for a defendant who presents evidence that his abnormal condition of the mind has substantially impaired behavioral controls. The second component completes the instruction and defines the ultimate issue, of exculpation, in terms of whether his behavioral controls were not only substantially impaired but impaired to such an extent that he lacked substantial capacity to conform his conduct to the law.39
b. The “result” of the mental disease
The rule contains a requirement of causality, as is clear from the term “result." Exculpation is established not by mental disease alone but only if “as a result” defendant lacks the substantial capacity required for responsibility. Presumably the mental disease of a kleptomaniac does not entail as a “result” a lack of capacity to conform to the law prohibiting rape.
c. At the time of the conduct.
Under the ALI rule the issue is not whether defendant is so disoriented or void of controls that he is never able to conform to external demands, but whether he had that capacity at the time of the conduct. The question is not properly put in terms of whether he would have capacity to conform in some untypical restraining situation — as with an attendant or policeman at his elbow. The issue is whether he was able to conform in the unstructured condition of life in an open society, and whether the result of his abnormal mental condition was a lack of substantial internal controls. These matters are brought out in the ALI’s comments to § 4.01 of the Model Penal Code Tentative Draft #4, p. 158:
The schizophrenic ... is disoriented from reality; the disorientation is extreme; but it is rarely total. Most psychotics will respond to a command of someone in authority within the mental hospital; they thus have some capacity to conform to a norm. But this is very different from the question whether they have the capacity to conform to requirements that are not thus immediately symbolized by an attendant or policeman at the elbow. Nothing makes the inquiry into responsibility more unreal for the psychiatrist than limitation of the issue to some ultimate extreme of total incapacity, when clinical experience reveals only a graded scale with marks along the way.
d. Capacity to appreciate wrongfulness of his conduct
As to the option of terminology noted in the ALI code, we adopt the formulation that exculpates a defendant *992whose mental condition is such that he lacks substantial capacity to appreciate the wrongfulness of his conduct. We prefer this on pragmatic grounds to “appreciate the criminality of his conduct” since the resulting jury instruction is more like that conventionally given to and applied by the jury. While such an instruction is of course subject to the objection that it lacks complete precision, it serves the objective of calling on the jury to provide a community judgment on a combination of factors. And since the possibility of analytical differences between the two formulations is insubstantial in fact in view of the control capacity test, we are usefully guided by the pragmatic considerations pertinent to jury instructions.40
In adopting the ALI formulation, this court does not follow the Currens opinion of the Third Circuit, which puts it that the sole issue in every case is defendant’s capacity to control his behavior, and that as a matter of analysis a person who lacks substantial capacity to appreciate the wrongfulness [criminality] of his conduct necessarily lacks substantial capacity to control his behavior. Like the other circuits, we resist the Currens lure of logic in order to make certain that the jury will give heed to the substantiality of a defense of lack of substantial capacity to appreciate wrongfulness, a point that may elude a jury instructed solely in terms of control capacity. In a particular case, however, defendant may have reason to request omission of the phrase pertaining to lack of capacity to appreciate wrongfulness, if that particular matter is not involved on the facts, and defendant fears that a jury that does not attend rigorously to the details of the instruction may erroneously suppose that the defense is lost if defendant appreciates wrongfulness. Here again, it is not enough to rely solely on logic, when a simple change will aid jury understanding. In such a case, if defendant requests, the judge should limit the instruction to the issue involved in that case, and charge that the jury shall bring in a verdict of not guilty if as a result of mental illness defendant lacked substantial capacity to conform his conduct to the requirements of the law.
e. Caveat paragraph
Section 4.01 of the Model Penal Code as promulgated by ALI contains in sub*993section (2) what has come to be known as the “caveat paragraph” :
(2) The terms “mental disease or defect” do not include an abnormality manifested only by repeated criminal or otherwise anti-social conduct.
The purpose of this provision was to exclude a defense for the so-called “psychopathic personality.” 41
There has been a split in the Federal circuits concerning this provision. Some of the courts adopting the ALI rule refer to both subsections but without separate discussion of the caveat paragraph — as in the Chandler and Blake opinions. As to the decisions considering the point, those of the Second and Third Circuits conclude the paragraph should be retained (in Freeman and Currens), while the Smith and Wade decisions, of the Sixth and Ninth Circuits, conclude it should be omitted. The Sixth Circuit’s position is (404 F.2d at 727, fn. 8) that there is “great dispute over the psychiatric soundness” of the caveat paragraph. The Wade opinion considers the matter at great length and puts forward three grounds for rejecting the caveat paragraph: (1) As a practical matter, it would be ineffectual in keeping sociopaths out of the definition of insanity; it is always possible to introduce some evidence, other than past criminal behavior, to support a plea of insanity.
(2) The criminal sanction ought not be sought for criminal psychopaths — constant recidivists — because such people should be taken off the streets indefinitely, and not merely for a set term of years. (3) Its third ground is stated thus (426 F.2d at 73):
It is unclear whether [the caveat paragraph] would require that a defendant be considered legally sane if, although the only overt acts manifesting his disease or defect were “criminal or otherwise anti-social,” there arises from his acts a reasonable inference of mental derangement either because of the nature of the acts or because of credible medical or other evidence.
Our own approach is influenced by the fact that our rule already includes a definition of mental disease (from McDonald). Under that definition, as we have pointed out, the mere existence of “a long criminal record does not excuse crime.” Williams v. United States, 114 U.S.App.D.C. 135, 137, 312 F.2d 862, 864 (1962). We do not require the caveat paragraph as an insurance against exculpation of the deliberate and persistent offender.42 Our McDonald rule guards against the danger of misunderstanding and injustice that might arise, say, from an expert’s classification that reflects only a conception43 defining all criminality as reflective of *994mental illness. There must be testimony to show both that the defendant was suffering from an abnormal condition of the mind and that it substantially affected mental or emotional processes and substantially impaired behavioral controls.
In this context, our pragmatic approach is to adopt the caveat paragraph as a rule for application by the judge, to avoid miscarriage of justice, but not for inclusion in instructions to the jury.
The judge will be aware that the criminal and antisocial conduct of a person — on the street, in the home, in the ward — is necessarily material information for assessment by the psychiatrist. On the other hand, rarely if ever would a psychiatrist base a conclusion of mental disease solely on criminal and anti-social acts. Our pragmatic solution provides for reshaping the rule, for application by the court, as follows: The introduction or proffer o.f past criminal and anti-social actions is not admissible as evidence of mental disease unless accompanied by expert testimony, supported by a showing of the concordance of a responsible segment of professional opinion, that the particular characteristics of these actions constitute convincing evidence of an underlying mental disease that substantially impairs behavioral controls.
This formulation retains the paragraph as a “caveat” rather than an inexorable rule of law. It should serve to obviate distortions of the present state of knowledge that would constitute miscarriages of justice. Yet it leaves the door open— on shouldering the “convincing evidence” burden — to accommodate our general rule to developments that may lie ahead. It is the kind of imperfect, but not unfeasible, accommodation of the abstract and pragmatic that is often found to serve the administration of justice.
We do not think it desirable to use the caveat paragraph as a basis for instructions to the. jury. It would be difficult for a juryman — or anyone else — to reconcile the caveat paragraph and the basic (McDonald) definition of mental disease if a psychiatrist testified that he discerned from particular past criminal behavior a pattern that established defendant as suffering from an abnormal condition of the mind that substantially impaired behavioral controls. If there is no such testimony, then there would be no evidence that mere misconduct betokens mental illness, it would be impermissible for defense counsel to present such a hypothesis to the jury, and there would be very little likelihood that a jury would arrive at such a proposition on its own. On the other hand, an instruction along the lines of the caveat paragraph runs the risk of appearing to call for the rejection of testimony that is based materially, but only partially, on the history of criminal conduct.
f. Broad presentation to the jury
Our adoption of the ALI rule does not depart from the doctrines this court has built up over the past twenty years to assure a broad presentation to the jury concerning the condition of defendant’s mind and its consequences. Thus we adhere to our rulings admitting expert testimony of psychologists,44 as well as psychiatrists, and to our many decisions contemplating that expert testimony on this subject will be accompanied by presentation of the facts and premises underlying the opinions and conclusions of the experts,45 and that the Government and defense may present, in Judge Blackmun’s words, “all possibly relevant evidence” bearing on cognition, volition and capacity.46 We agree with the amicus submission of the National District Attorneys Association *995that the law cannot “distinguish between physiological, emotional, social and cultural sources of the impairment” — assuming, of course, requisite testimony establishing exculpation under the pertinent standard — and all such causes may be both referred to by the expert and considered by the trier of fact.47
Breadth of input under the insanity defense is not to be confused with breadth of the doctrines establishing the defense. As the National District Attorneys Association brief points out, the latitude for salient evidence of e. g., social and cultural factors pertinent to an abnormal condition of the mind significantly affecting capacity and controls, does not mean that such factors may be taken as establishing a separate defense for persons whose mental condition is such that blame can be imposed. We have rejected a broad “injustice” approach that would have opened the door to expositions of e. g., cultural deprivation, unrelated to any abnormal condition of the mind.
We have recognized that “Many criminologists point out that even normal human behavior is influenced by such factors as training, environment, poverty and the like, which may limit the understanding and options of the individual.” King v. United States, supra, 125 U.S.App.D.C. at 323, 372 F.2d at 388. Determinists may contend that every man’s fate is ultimately sealed by his genes and environment, over which he has no control. Our jurisprudence, however, while not oblivious to deterministic components, ultimately rests on a premise of freedom of will. This is not to be viewed as an exercise in philosophic discourse, but as a governmental fusion of ethics and necessity, which takes into account that a system of rewards and punishments is itself part of the environment that influences and shapes human conduct. Our recognition of an insanity defense for those who lack the essential, threshold free will possessed by those in the normal range is not to be twisted, directly or indirectly, into a device for exculpation of those without an abnormal condition of the mind.
Finally, we have not accepted suggestions to adopt a rule that disentangles the insanity defense from a medical model, and announces a standard exculpating anyone whose capacity for control is insubstantial, for whatever cause or reason. There may be logic in these submissions, but we are not sufficiently certain of the nature, range and implications of the conduct involved to attempt an all-embracing unified field theory. The applicable rule can be discerned as the cases arise in regard to other conditions — somnambulism or other automatisms; blackouts due, e. g. to overdose of insulin; drug addiction. Whether these somatic conditions should be governed by a rule comparable to that herein set forth for mental disease would require, at a minimum, a judicial determination, which takes medical opinion into account, finding convincing evidence of an ascertainable condition characterized by “a broad consensus that free will does not exist.” Salzman v. United States, 131 U.S.App.D.C. 393, 400, 405 F.2d 358, 365 (1968) (concurring opinion of Judge Wright).
E. Inter-related Doctrines and Implementing Instructions
For sake of clarity, and to obviate misunderstanding and unnecessary litigation, we undertake by today’s ruling to accompany our definition of the underlying doctrine on insanity as a defense negativing criminal responsibility, with comments on implementing instructions and certain inter-related doctrines as they will stand hereafter.
1. Suggested instruction
Appendix B contains a suggested instruction in the thought that the trial judges may consider it useful for their consideration and guidance in the *996task of making the adjustments in practices and routines required by our ruling.
Burden of Proof
Appendix B contains alternate wordings on burden of proof. One wording conforms to the doctrine of Davis v. United States, 160 U.S. 469, 16 S.Ct. 353, 40 L.Ed. 499 (1895), that the Government has the burden of proving beyond a reasonable doubt that the defendant was not entitled to exculpation as a result of his mental disease or defect. The other version is cast in the wording of the last sentence of 24 D.C.Code § 301 (j), as added to the law in 1970: 48 “No person accused of an offense shall be acquitted on the ground that he was insane at the time of its commission unless his insanity, regardless of who raises the issue, is affirmatively established by a preponderance of the evidence.”
Questions have been raised as to the constitutionality of this 1970 provision,49 its applicability to offenses committed prior to the 1970 enactment, and its applicability to offenses committed in the District of Columbia which are not violations of the D.C.Code but are violations of the United States Code.50 We do not think it appropriate to decide such questions at this time, and accordingly have provided alternate versions in the instruction suggested in Appendix B.
2. The “Lyles” instruction — as to effect of verdict of not guilty by reason of insanity
By a statute of August 9, 1955, passed in the wake of Durham, Congress added to 24 D.C.Code § 301, provisions on mandatory commitment of persons acquitted by reason of insanity, set forth in subsection (d), and provisions governing the release of persons so committed, set forth in subjection (e).
In Lyles v. United States, 103 U.S.App.D.C. 22, 254 F.2d 725 (en banc, 1957), the majority of the court concurred in Part I of the opinion filed by Judges Prettyman and Burger that the jury, which knows the meaning of a verdict of guilty and not guilty “has a right to know the meaning of [the insanity] verdict as accurately as it knows by common knowledge the meaning of the other two possible verdicts.” The court said, 103 U.S.App.D.C. at 25, 254 F.2d at 728:
We think that when the instruction is given the jury should simply be informed that a verdict of not guilty by reason of insanity means that the accused will be confined in a hospital for the mentally ill until the superintendent has certified, and the court is satisfied, that such person has recovered his sanity and will not in the reasonable future be dangerous to himself or others, in which event and at which time the court shall order his release either unconditionally or under such conditions as the court may see fit.
The court provided for omission of such an instruction on the affirmative request of a defendant. vi
Bolton v. Harris, 130 U.S.App.D.C. 1, 395 F.2d 642 (1968) read § 301(d) as permitting mandatory commitment for the purpose of a mental examination, but as containing a requirement of a judicial hearing, on the question of whether the defendant involved ought to be retained *997in custody on the basis of his current mental condition, with procedures substantially similar to those in proceedings, under 21 D.C.Code § 545(b), for civil commitment of the dangerous mentally ill. The court also construed § 301(e) to entitle the patient to periodic examinations by the hospital staff, to an examination by an outside psychiatrist, and to a court hearing if any one of the examining physicians believes he should no longer be hospitalized.
Finally, the court construed § 301(g), reserving the right of a confined person to establish eligibility for release under this section by habeas corpus, to require the person confined to prove by a preponderance of the evidence that his detention is illegal. “Thus, the court must find, by the preponderance of the evidence, that the patient’s commitment is no longer valid — i. e., that he is no longer ‘likely to injure himself or other persons’ due to ‘mental illness.’ ” (130 U.S.App.D.C. at 12, 395 F.2d at 653.) The Court referred to its ruling as similar to that in the concurring opinion of Judge Fahy in Ragsdale v. Overholser, 108 U.S.App.D.C. 308, 315, 281 F.2d 943, 950 (1960).
As to the Lyles instruction, the Bolton opinion (at note 50) held that it should be changed to comport with the procedures then construed to be required under the law. The D.C. Court Reform and Criminal Procedure Act of 1970, P.L. 91-358, retained what was formerly § 301(d) as § 301(d)(1) of 24 D.C. Code, and retained § 301(e) unchanged. Accordingly, the 1970 law retains the Bolton v. Harris construction of what is now § 301(d)(1), as providing mandatory commitment for the purpose of examination, and its construction of § 301 (e), as to provisions for release. However, the 1970 law adds a new provision, see 24 D.C.Code § 301(d)(2):
(2) A person confined pursuant to paragraph (1) shall have a hearing, unless waived, within 50 days of his confinement to determine whether he is entitled to release from custody. At the conclusion of the criminal action referred to in paragraph (1) of this subsection, the court shall provide such person with representation by counsel—
(A) in the case of a person who is eligible to have counsel appointed by the court, by continuing any appointment of counsel made to represent such person in the prior criminal action or by appointing new counsel; or
(B) in the case of a person who is not eligible to have counsel appointed by the court, by assuring representation by retained counsel.
If the hearing is not waived, the court shall cause notice of the hearing to be served upon the person, his counsel, and the prosecuting attorney and hold the hearing. Within ten days from the date the hearing was begun, the court shall determine the issues and make findings of fact and conclusions of law with respect thereto. The person confined shall have the burden of proof. If the court finds by a preponderance of the evidence that the person confined is entitled to his release from custody, either conditional or unconditional, the court shall enter such order as may appear appropriate.
Section 301(d)(2), as added in 1970, gives specific implementation to the construction of Bolton v. Harris, which requires a judicial hearing, following the initial examination, prior to an order of mandatory commitment under 301(d). It differs to the extent that Bolton v. Harris contemplated a burden of proof on the Government in 301(d) commitment proceedings, like that in civil commitment proceedings. Section 301(d)(2) now provides that the person confined “shall have the burden of proof” — to establish eligibility for release under the standards of § 301(e). Accordingly the Lyles instruction must be recast as to persons governed by the 1970 law. This is a suggested form:
If the defendant is found not guilty by reason of insanity, it becomes the duty of the court to commit him to St. Elizabeths Hospital. There will be a *998hearing within 50 days to determine whether defendant is entitled to release. In that hearing the defendant has the burden of proof. The defendant will remain in custody, and will be entitled to release from custody only if the court finds by preponderance of the evidence that he is not likely to injure himself or other persons due to mental illness.
As to the possibility of an attack onJ the constitutionality of § 301(d)(2), that question has not been briefed or argued, and it is not now being decided.51
3. Mental condition, though insufficient to exonerate, may be relevant to specific mental element of certain crimes or degrees of crime.
Our decision accompanies the redefinition of when a mental condition exonerates a defendant from criminal responsibility with the doctrine that expert testimony as to a defendant’s abnormal mental condition may be received and considered, as tending to show, in a responsible way, that defendant did not have the specific mental state required for a particular crime or degree of crime —even though he was aware that his act was wrongful and was able to control it, and hence was not entitled to complete exoneration.
Some of the cases following this doctrine use the term “diminished responsibility,” but we prefer the example of the eases that avoid this term (e. g., note 57, infra), for its convenience is outweighed by its confusion: Our doctrine has nothing to do with “diminishing” responsibility of a defendant because of his impaired mental condition,52 but rather with determining whether the defendant had the mental state that must be proved as to all defendants.
Procedurally, the issue of abnormal mental condition negativing a person’s intent may arise in different ways: For example, the defendant may offer evidence of mental condition not qualifying as mental disease under McDonald. Or he may tender evidence that qualifies under McDonald, yet the jury may conclude from all the evidence that defendant has knowledge and control capacity sufficient for responsibility under the ALI rule.
The issue often arises with respect to mental condition tendered as negativing the element of premeditation in a charge of first degree premeditated murder. As we noted in Austin v. United States, 127 U.S.App.D.C. 180, 382 F.2d 129 (1967), when the legislature modified the common law crime of murder so as to establish degrees, murder in the first degree was reserved for intentional homicide done deliberately and with premeditation, and homicide that is intentional but “impulsive,” not done after “reflection and meditation,” was made murder only in the second degree. (127 U.S.App.D.C. at 187, 382 F.2d at 135).
An offense like deliberated and premeditated murder requires a specific intent that cannot be satisfied merely by showing that defendant failed to conform to an objective standard.53
*999This is plainly established by the defense of voluntary intoxication. In Hopt v. Utah, 104 U.S. 631, 634, 26 L.Ed. 873 (1881), the Court, after stating the familiar rule that voluntary intoxication is no excuse for crime, said:
[W]hen a statute establishing different degrees of murder requires deliberate premeditation in order to constitute murder in the first degree, the question of whether the accused is in such a condition of mind, by reason of drunkenness or otherwise, as to be capable of deliberate premeditation, necessarily becomes a material subject of consideration by the jury.
In Bishop v. United States, 71 App.D.C. 132, 136, 107 F.2d 297, 301 (1939), Justice Vinson noted that while voluntary intoxication per se is no defense to guilt, “the stated condition of a defendant’s mind at the time of the killing . is now a proper subject for consideration, inquiry, and determination by the jury.” Thus “voluntary intoxication will not excuse murder, but it may negative the ability of the defendant” as to premeditation, and hence effect “a reduction to second degree murder.”
Enlarging on Hopt and Bishop, Judge Burger’s opinion in Heideman v. United States, 104 U.S.App.D.C. 128, 131, 259 F.2d 943, 946 (1958), points out:
Drunkenness is not per se an excuse for crime, but nevertheless it may in many instances be relevant to the issue of intent. One class of cases where drunkenness may be relevant on the issue of intent is the category of crimes where specific intent is required. Robbery falls into this category, and a defendant accused of robbery is entitled to an instruction on drunkenness as bearing on intent if the evidentiary groundwork has been adequately laid.
As Judge Burger points out there must be a showing of drunkenness that does more than remove inhibitions, and is such an “incapacitating state” as to negate intent.' But he also notes, citing Hopt, and Bishop, that a lesser state of drunkenness, insufficient to negate the specific intent required for robbery, may suffice to negate the premeditation required for first degree murder.
Neither logic nor justice can tolerate a jurisprudence that defines the elements of an offense as requiring a mental state such that one defendant can properly argue that his voluntary drunkenness removed his capacity to form the specific intent but another defendant is inhibited from a submission of his contention that an abnormal mental condition, for which he was in no way responsible, negated his capacity to form a particular specific intent, even though the condition did not exonerate him from all criminal responsibility.
In Fisher v. United States, 80 U.S.App.D.C. 96, 149 F.2d 28 (1946), the court upheld the trial court’s refusal to instruct the jury that on issues of premeditation and deliberation “it should consider the entire personality of the defendant, his mental, nervous, emotional and physical characteristics as developed by the evidence in the case.” Justice Arnold’s abbreviated opinion was evidently premised on two factors: (1) that the instruction confused the issue of insanity with the issue of deliberation; (2) that “To give an instruction like the above is to tell the jury they are at liberty to acquit one who commits a brutal crime because he has the abnormal tendencies of persons capable of such crimes.” His opinion made no effort to come to terms with the Hopt opinion, stressed by Fisher’s counsel.
Fisher went to the Supreme Court and there was affirmed, but on the limited ground of disinclination to “force” this court in a choice of legal doctrine for the District of Columbia, 328 U.S. 463, 66 S.Ct. 1318, 90 L.Ed. 1382 (1946). The Court said (at 476, 66 S.Ct. at 1325) that such a change was “more properly a *1000subject for the exercise of legislative power or at least for the discretion of the courts of the District.”
In Stewart I, Stewart v. United States, 94 U.S.App.D.C. 293, 214 F.2d 879 (1954) which issued only two weeks after Durham was announced, we said that “reconsideration of our decision in Fisher should wait until we can appraise the results [of Durham].” In Stewart v. United States, 107 U.S.App.D.C. 159, 275 F.2d 617 (1960), the court en banc again stated that more experience with Durham was required to evaluate Fisher, and the matter was appropriate for legislative consideration. That was Stewart II.54
Today we are again en banc, and we have the benefit of many years of experience with Durham-McDonald. We are changing the insanity rule, on a prospective basis, to take into account intervening scholarship and court opinions. As a corollary, we deem it appropriate to change the rule of Fisher on a prospective basis, and to accept the approach which the Supreme Court declined to “force” upon us in 1946, but which has been adopted by the overwhelming majority of courts that have recently faced the question. We are convinced by the analysis set forth in the recent opinions of the highest courts of California,55 Colorado,56 New Jersey,57 Iowa,58 Ohio,59 Idaho,60 Connecticut,61 Nebraska,62 New Mexico63 and Nevada.64 They have joined the states that spoke out before Fisher — New York, Rhode Island, Utah, Wisconsin and Wyoming.65
The pertinent reasoning was succinctly stated by the Colorado Supreme Court as follows:66
The question to be determined is not whether defendant was insane, but whether the homicidal act was committed with deliberation and premeditation. The evidence offered as to insanity may or may not be relevant to that issue. * * * “A claim of insanity cannot be used for the purpose of reducing a crime of murder in the first degree to murder in the second degree or from murder to manslaughter. If the perpetrator is responsible at all in this respect, he is responsible in the same degree as a sane man; and *1001if he is not responsible at all, he is entitled to an acquittal in both degrees. However, . . . evidence of the condition of the mind of the accused at the time of the crime, together with the surrounding circumstances, may be introduced, not for the purpose of establishing insanity, but to prove that the situation was such that a specific intent was not entertained — that is, to shoiv absence of any deliberate or premeditated design.” (Emphasis in original.)
On the other side of the coin, very few jurisdictions which have recently considered this question have held to the contrary position.67
Intervening developments within our own jurisdiction underscore the soundness of a doctrine for consideration of abnormal mental condition on the issue of specific intent. In the Fisher opinion of 1946, the court was concerned lest such a doctrine “tell the jury that they are at liberty to acquit one who commits a brutal crime because he has the abnormal tendencies of persons capable of such crimes.” |jThat a man’s abnormal mental condition short of legal insanity may be material as negativing premeditation and deliberation does not set him “at liberty” but reduces the degree of the criminal homicide^ Our 1967 opinion in Austin, supra, clarifies that even “a particularly frightful and horrible murder” may not be murder in the first degree, that “many murders most brutish and bestial are committed in a consuming frenzy or heat of passion, and that these are in law only murder in the second degree.”68 Indeed the action of the trial judge in acquitting defendant of first degree murder indicates how the refinement of Austin has undercut the Fisher approach. Though the defendant went back to get his gun,69 the judge concluded that the evidence as a whole — including defendant’s broken jaw, the blood streaming down his face, and his irrational pounding on the mailbox — did not establish a reasonable foundation for inferring a calculated, deliberate mind at the time of shooting. We are not called upon to consider whether that action was proper in this case; what we do take note of is the inevitable implication of Austin.
There has also been a material legislative development since both Fisher and Stewart II. In 1964, after extensive hearings, Congress enacted the Hospitalization of the Mentally 111 Act, which provides civil commitment for the “mentally ill” who are dangerous to themselves or others.70 Both the terminology and the underlying conception of this statute reflected a deliberate change from the 1939 law and its use of the term “insanity,” which prior to Durham tended to be equated to psychosis and to dis-orientations like delusions. The enlarged conception underlying the 1964 law has been accorded a “liberal construction” 71 for the protection of the community, going so far as to include commitment of a disturbed mental defective with behavioral reactions resulting in danger-productive behavior.72 The law is broad enough to include not only mental illness requiring confinement in St. Elizabeths, but also conditions of mental illness calling for placement in nursing homes,73 or, where appropriate, halfway houses or requirement of outpatient care.74 These statutory provisions provide a shield against danger from per*1002sons with abnormal mental condition — a danger which in all likelihood bolstered, or even impelled, the draconic Fisher doctrine.
Further, to the extent that the 1970 law (supra,, note 48) leads to a conviction of first degree murder when the evidence is in equipoise on the issue of insanity, there would be an additional miscarriage of justice if "the evidence were not available for consideration as raising a reasonable doubt on the issue of premeditation and deliberation.
In providing for the admission and consideration of expert testimony on abnormal mental condition insufficient for complete exoneration, we insert some observations prompted by State v. Sikora, 44 N.J. 453, 210 A.2d 193 (1965), supra, note 57. The doctrine does not permit the receipt of psychiatric testimony based on the conception that mental disorder is only a relative concept and that the behavior of every individual is dictated by forces — ultimately, his genes and lifelong environment — that are unconscious and beyond his control. As we have already made clear, we are not embarked on enquiry that must yield to tenets of the philosophy of determinism. The law accepts free will and blameworthiness as a general premise: Expert psychiatric testimony negativing blameworthiness for a crime — whether on ground of general exoneration or lack of requisite specific intent — must rest on the premise of an exception due to abnormal mental condition.
Our rule permits the introduction of expert testimony as to abnormal condition if it is relevant to negative, or establish, the specific mental condition that is an element of the crime. The receipt of this expert testimony to negative the mental condition of specific intent requires careful administration by the trial judge. Where the proof is not offered in the first instance as evidence of exonerating mental disease or defect within the ALI rule the judge may, and ordinarily would, require counsel first to make a proffer of the proof to be adduced outside the presence of the jury. The judge will then determine whether the testimony is grounded in sufficient scientific support to warrant use in the courtroom, and whether it would aid the jury in reaching a decision on the ultimate issues.75
*1003F. Disposition of the Case
1. Issue of Causality Testimony
We are urged to reverse appellant’s conviction on the ground that the trial court erred in allowing Government experts to testify in terms of “causality.”
The rule of Washington v. United States, 129 U.S.App.D.C. 29, 390 F.2d 444 (1967) that experts must not frame their testimony in terms of “product,” was aimed at relieving a stubborn and recurring problem — that of experts using their facility with the' esoteric and imprecise language of mental disease to exert an undue dominion over the jury’s deliberations. The Washington opinion did not refer to the prior opinion in Harried v. United States, 128 U.S.App.D.C. 330, 389 F.2d 281 (1967), wherein the court stated that narrowly drawn, concrete questions addressed to the experts on the causal connection between the forbidden act and the alleged mental disease were permissible.
Since both Washington and Harried are superseded — on this point— by our change today of the ultimate rule, it would be bootless to consider to what extent Washington superseded Harried. It suffices for disposition of this case to say only: (1) Under the rule of Harried the questioning of Government experts on the question of the causal eon-' nection between appellant’s crime and his mental disease or defect was proper. (2) Assuming, arguendo, that these questions were not consonant with Washington we are unable, on this record, to discern prejudice. We think the expert testimony in this case adequately and lucidly ventilated the issues, there was no use of the term “product,” and we see no sign of overreaching.76
Our conclusion is also impelled by the fact that it was defendant himself who first sought expert testimony on the question of causal connection. The doctrine of curative admissibility rests upon “the necessity of removing prejudice in the interest of fairness,” United States v. Winston, 145 U.S.App.D.C. 67, 447 F.2d 1236, 1240 (1971), quoting Crawford v. United States, 91 U.S.App.D.C. 234, 237, 198 F.2d 976, 979 (1952). In this case, the interests of fairness were served by permitting additional inquiry on the subject of the relationship between the murder and the appellant’s mental status. Defense questioning established that, in the opinion of defense experts, there was a causal connection between the act and the defendant’s mental disorder. It would be unfair, and against the interest of justice, for us to hold that the jury had to retire to consider the case believing that this question was beyond medical dispute.
2. Prosecutor’s conduct
It is also urged upon us that reversal of appellant’s conviction is required because the prosecutor went beyond the limits of the permissible in his summation, by attempting to discredit the projective tests the St. Elizabeths psychologist had given to the defendant. Excerpts from this summation are set out in a footnote.77
*1004It is unfortunate that the prosecutor’s summation incorporated, as an approach to the projective tests: “After all, they are just blots of ink.” The prosecutor, who speaks in court in behalf of the public interest, has a responsibility to refrain from know-nothing appeals to ignorance. The prosecutor is not free to offer his own opinions and attitudes on matters of expert knowledge, even in camouflaged form. The prosecutor was free to adduce appropriate expert testimony, on direct or cross-examination, to attack the validity of such tests, or perhaps to adduce limitations on their value and significance. However, in this trial the prosecutor’s cross-examination was not oriented in that manner, but sought rather to probe the basis for the expert’s conclusion, and his use of the tests. That was an entirely permissible course, particularly since the witness agreed that interpretation of the tests involves a subjective evaluation, over and above the underlying training and expertise of the expert. But there was neither testimony adduced on cross-examination, nor testimony of a prosecutor's witness, to support a disparagement of the very concept of projective tests, as based on mere ink blots.
While the prosecutor’s summation contains an approach we do not expect to recur, it was neither as aggravated nor as prolonged as that in King.78 And the record context includes clarifying questions by the trial judge that brought out for the jury both the long and widespread use of projective tests, and their use as a basis for this expert’s conclusions. We do not find reversible error.
3. Remand
Our action today in stating a new rule for insanity, and for receipt and consideration of expert testimony on *1005abnormal mental condition that does not establish an insanity defense but is material to a substantive element of the offense, is effective prospectively for all trials beginning after this date.79 However, under established doctrines of the judicial function we conclude that the benefit of the rule cannot wholly be withheld from the defendant in whose case it was established.80 We do not, however, think it appropriate for us to determine at this juncture whether a jury which convicted under our old insanity standard might have acquitted under the new standard. While we hesitate to burden the trial judge further, we are remanding to the trial judge to determine whether a new trial is appropriate in the interest of justice, rather than considering that question at the appellate level in the first instance, because the trial judge has a superior vantage point for assessing whether there is a substantial possibility that the jury, if instructed under our new rule, would have found that appellant should be acquitted by reason of insanity. If a new trial is denied, the trial judge will re-enter a judgment on the verdict of guilty 81
G. Supplement To Clarify Matters Discussed in Separate Opinion
A number of matters are discussed in the separate opinion of Chief Judge *1006Bazelon. For the most part, where that opinion takes issue with the approach of the majority opinion the issue is reasonably clearly joined and refinement or elaboration would be in the service of rhetoric rather than clarity. Certain passages of the separate opinion, however, set forth a view of the majority opinion which is not congruent with its intent or thrust as understood by the judges subscribing to that opinion. The matters most requiring comment, in order to avoid a misinference that supposes that failure to speak means acquiescence, are as follows:
1. The court’s failure to discuss various procedural aspects of the insanity defense and its presentation reflects neither unawareness nor indifference. As the questions communicated through the Clerk (Appendix A) make clear, however, this review en banc was intended to focus on the ultimate standard, and not to expatiate broadly on the administration of the insanity defense. There is no intent to override various decisions of this court, evolved during the past twenty years, on matters of procedure and administration that are important, to be sure, but do not turn on the ultimate standard. And of course we always contemplate improvements ahead, in all aspects of the administration of justice. It is our belief that they can be both accommodated within and enhanced by a context that defines the governing standard as avoiding the conviction as criminals of those who as a result of mental disease or defect lack substantial capacity to control the criminal behavior in question (or to appreciate its wrongfulness).
2. The goal of avoiding undue dominance of the jury by expert testimony does not require ostrich disregard of the key issue of causality. That issue, however, is focused more meaningfully, for both expert and jury, by asking whether the mental disease or defect resulted in lack of substantial capacity to control the behavior in question (or appreciate its wrongfulness). The question is differently put under Durham, and the difference has proved to be both confusing and significant. The issue today is not whether this confusion could or should have been foreseen, but whether it shall be corrected. The rule contemplating expert testimony as to the existence and consequence of a mental disease or defect is not to be construed as permission to testify solely in terms of expert conclusions. Our jurisprudence to the contrary is not undone, it is rather underscored. It is the responsibility of all concerned — expert, counsel and judge —to see to it that the jury in an insanity case is informed of the expert’s underlying reasons and approach, and is not confronted with ultimate opinions on a take-it-or-leave-it basis. The Appendix to Washington is useful in this regard— assuming appropriate modification of the third paragraph, which uses the “product” term.82 It clarifies the respective roles of the legal and medical professions, and perhaps helps achieve the goal envisaged by Sir James FitzJames Stephen: “In dealing with matters so obscure and difficult the two great professions ought rather to feel for each other’s difficulties than to speak harshly of each other’s shortcomings.” 83
The Appendix to Washington still stands in effect, although we do not retain Washington insofar as it reflects the product rule, and we permit testimony by the expert, and cross-examination, *1007on the causal relationship between the mental disease and the existence of substantial capacity .for control (and knowledge) at the time of the act. The jury will consider this testimony under the instruction on need to acquit if as a result of mental disease or defect there is a lack of substantial capacity to control the behavior in question (or appreciate its wrongfulness). We think this sufficiently communicates to the jury the kind of hard question it is called upon to decide, and the instructions will make clear that the jury is not foreclosed by opinions of experts. The experts add to perspective, without governing decision. The law looks to the experts for input, and to the jury for outcome.
* * *
The case is remanded for further consideration by the District Court in accordance with this opinion.
So ordered.
APPENDIX A
Letter of February 5, 1971, from the Clerk to organizations invited to make a submission amicus curiae.
The Court has directed me to request you to discuss in your briefs the following questions:
1. In this case all four expert witnesses testified on the issue of “productivity.” See Transcript pp. 335-36, 464-65, 506-07, 539. But see bench colloquy at 314-15. Assuming arguendo that this testimony violated the rule of Washington v. United States, 129 U.S.App.D.C. 29, 390 F.2d 444 (1967), is the Washington rule a viable device for limiting the role of the expert and preserving the ultimate question of criminal responsibility for the jury? Would it be more effective simply to eliminate the separate inquiry into productivity from our test of responsibility? See United States v. Eichberg, 142 U.S.App.D.C. 110 at 117, 118, 439 F.2d 620 at 627, 628 (Decided Jan. 21, 1971) (concurring opinion).
2. What are the theoretical and practical differences between the Durham-McDonald test of criminal responsibility, the ALI test, and the various other tests that have been proposed in recent years by courts and commentators ?
3. Should the Durham-McDonald formulation be retained as it is ?
4. Should the ALI formulation be adopted ?
5. If so, should the McDonald definition of “mental disease or defect” be applied to the ALI formulation ?
6. If a defendant’s behavior controls are impaired, should a test of criminal responsibility distinguish between physiological, emotional, social, and cultural sources of the impairment? See Transcript pp. 409-11, 477-79. Is it appropriate to tie a test of criminal responsibility to the medical model of mental illness? See United States v. Eichberg, supra, 142 U.S.App.D.C. at 116, 117, 439 F.2d at 626, 627.
7. Should the results of psychological tests such as the Rorschach test be admissible in evidence? If so, what kind of testimony is necessary or appropriate in order to put the test results in proper perspective? See Transcript pp. 318-329, 342-350, 413-452.
8. Have we departed in practice, if not in theory, from the rule that the government has the burden of proving criminal responsibility beyond a reasonable doubt? See United States v. Eichberg, supra, 142 U.S.App.D.C. at 113-116, 439 F.2d at 623-626.
9. Would it be sound as a matter of policy to abolish the insanity defense? Possible as a matter of law? If so, what are the possible alternatives? Should the issues presently treated under that heading be subsumed under the inquiry into mens rea? Should we reconsider the possibility of “diminished” or “partial” responsibility ?
Should you wish a copy of the transcript, I should be pleased to furnish it to you if you intend to submit and file a brief.
Sincerely yours, Nathan J. Paulson Clerk
*1008APPENDIX B
SUGGESTION FOR INSTRUCTION ON INSANITY *
The defendant in this ease asserts the defense of insanity.
You are not to consider this defense unless you have first found that the Government has proved beyond a reasonable doubt each essential element of the offense. One of these elements is the requirement [of premeditation and deliberation for first degree murder] [or of specific intent for -], on which you have already been instructed. In determining whether that requirement has been proved beyond a reasonable doubt you may consider the testimony as to the defendant’s abnormal mental condition.
If you find that the Government has failed to prove beyond a reasonable doubt any one or more of the essential elements of the offense, you must find the defendant not guilty, and you should not consider any possible verdict relating to insanity.
If you find that the Government has proved each essential element of the offense beyond a reasonable doubt, then you must consider whether to bring in a verdict of not guilty by reason of insanity.
The law provides that a jury shall bring in a verdict of not guilty by reason of insanity if, at the time of the criminal conduct, the defendant, as a result of mental disease or defect, either lacked substantial capacity to conform his conduct to the requirements of the law, or lacked substantial capacity to appreciate the wrongfulness of his conduct.
Every man is presumed to be sane, that is, to be without mental disease or defect, and to be responsible for his acts. But that presumption no longer controls when evidence is introduced that he may have a mental disease or defect.
The term insanity does not require a showing that the defendant was disoriented as to time or place.
Mental disease [or defect] includes any abnormal condition of the mind, regardless of its medical label, which substantially affects mental or emotional processes and substantially impairs behavior controls. The term “behavior controls” refers to the processes and capacity of a person to regulate and control his conduct and his actions.
In considering whether the defendant had a mental disease [or defect] at the time of the unlawful act with which he is charged, you may consider testimony in this ease concerning the development, adaptation and functioning of these mental and emotional processes and behavior controls.
[The term “mental disease” differs from “mental defect” in that the former is a condition which is either capable of improving or deteriorating and the latter is a condition not capable of improving or deteriorating.]
[Burden of proof — alternate versions :
(a) The burden of proof is on the defendant to establish by a preponderance of the evidence that, as a result of mental disease or defect, he either lacked substantial capacity to conform his conduct to the requirements of the law or lacked substantial capacity to appreciate the wrongfulness of his conduct. If defendant has met that burden you shall bring in a verdict of not guilty by reason of insanity. If he has not met that burden you shall bring in a verdict of guilty of the offenses you found proved beyond a reasonable doubt.
(b) The burden is on the Government to prove beyond a reasonable doubt either that the defendant was not suffering from a mental disease or defect, or else that he nevertheless had *1009substantial capacity both to conform his conduct to the requirements of the law and to appreciate the wrongfulness of his conduct. If the Government has not established this beyond a reasonable doubt, you shall bring in a verdict of not guilty by reason of insanity.]
Evaluation of Testimony
In considering the issue of insanity, you may consider the evidence that has been admitted as to the defendant’s mental condition before and after the offense charged, as well as the evidence as to defendant’s mental condition on that date. The evidence as to the defendant’s mental condition before and after that date was admitted solely for the purpose of assisting you to determine the defendant’s condition on the date of the alleged offense.
You have heard the evidence of psychiatrists [and psychologists] who testified as expert witnesses. An expert in a particular field is permitted to give his opinion in evidence. In this connection, you are instructed that you are not bound by medical labels, definitions, or conclusions as to what is or is not a mental disease [or defect]. What psychiatrists [and psychologists] may or may not consider a mental disease [or defect] for clinical purposes, where their concern is treatment, may or may not be the same as mental disease [or defect] for the purpose of determining criminal responsibility. Whether the defendant had a mental disease [or defect] must be determined by you under the explanation of those terms as it has been given to you by the Court.
There was also testimony of lay witnesses, with respect to their observations of defendant’s appearance, behavior, speech, and actions. Such persons are permitted to testify as to their own observations and other facts known to them and may express an opinion based upon those observations and facts known to them. In weighing the testimony of such lay witnesses, you may consider the circumstances of each witness, his opportunity to obseive the defendant and to know the facts to which he has testified, his willingness and capacity to expound freely as to his observations and knowledge, the basis for his opinion and conclusions, and the nearness or remoteness of his observations of the defendant in point of time to the commission of the offense charged.
You may also consider whether the witness observed extraordinary or bizarre acts performed by the defendant, or whether the witness observed the defendant’s conduct to be free of such extraordinary or bizarre acts. In evaluating such testimony, you should take into account the extent of the witness’s observation of the defendant and the nature and length of time of the witness’s contact with the defendant. You should bear in mind that an untrained person may not be readily able to detect mental disease [or defect] and that the failure o.f a lay witness to observe abnormal acts by the defendant may be significant only if the witness had prolonged and intimate contact with the defendant.
You are not bound by the opinions of either expert or lay witnesses. You should not arbitrarily or capriciously reject the testimony of any witness, but you should consider the testimony of each witness in connection with the other evidence in the case and give it such weight as you believe it is fairly entitled to receive.
You may also consider that every man is presumed to be sane, that is, to be without mental disease [or defect], and to be responsible for his acts. You should consider this principle in the light of all the evidence in the case and give it such weight as you believe it is fairly entitled to receive.
Effect of verdict of not guilty by reason of insanity
If the defendant is found not guilty by reason of insanity, it becomes the duty of the court to commit him to St. Elizabeths Hospital. There will be a hearing within 50 days to determine whether defendant is entitled to release. *1010In that hearing the defendant has the burden of proof. The defendant will remain in custody, and will be entitled to release from custody only if the court finds by preponderance of the evidence that he is not likely to injure himself or other persons due to mental illness.
Note: If the defendant so requests, this instruction need not be given.
. McDonald v. United States, 114 U.S.App.D.C. 120, 312 F.2d 847 (en banc, 1962).
. United States v. Lee, 15 D.C. 489, 490 (1886):
The rule of law is very plain that in order that the plea of insanity shall prevail, there must have been that mental condition of the party which disabled him from distinguishing between right and wrong in respect of the act committed.
. Smith v. United States, 59 App.D.C. 144, 145, 36 F.2d 548, 549 (1929) :
[it must be found that defendant’s] reasoning powers were so far dethroned by his diseased mental condition as to deprive him of the will power to resist the insane impulse to perpetrate the deed, though knowing it to be wrong.
. 10 Clark & F. 200, 2 Eng.Rep. 718 (H.L. 1843).
. A. Goldstein, The Insanity Defense 54 (1967), citing 1 Wigmore Evidence § 228 (1940) and numerous cases.
. Durham contemplated from the start that tlie jury would have the guidance of “wider horizons of knowledge” from the medical experts than was available under the prior rule, but that in the last analysis the ultimate question is left to the jury “to perform its traditional function ... to apply ‘our inherited ideas of moral responsibility to individuals prosecuted for crime.’ [Juries will] continue to make moral judgments. . . . ” 94 U.S.App.D.C. at 242, 214 F.2d at 876. See also, King v. United States, 125 U.S.App.D.C. 318 at 323-324, 372 F.2d 383 at 388-389 “The question for the jury requires the application to medical knowledge, and the lay evidence as well, of the understanding and judgment of the community as reflected in the jury. . . . [In] view of the complicated nature of the decision to be made — intertwining moral, legal, and medical judgments — it will require an unusually strong showing to induce us to reverse a conviction because the judge left the critical issue of responsibility with the jury.”
Holloway v. United States, 80 U.S.App. D.C. 3, 4, 148 F.2d 665, 666 (1945) :
“Legal tests of criminal insanity are not and cannot be the result of scientific analysis or objective judgment. They must be based on the instinctive sense of justice of ordinary men. This sense of justice assumes that there is a faculty called reason which is separate and apart from instinct, emotion, and impulse, that enables' an individual to distinguish between right and wrong and endows him with moral responsibility for his acts. . . . Our collective conscience does not allow punishment where it cannot impose blame.”
Sauer v. United States, 241 F.2d 640, 649 (9th Cir. 1957), quoting Holloway, refers to the court’s “awareness that the jury will eventually exercise a moral judgment as to the sanity of the accused.”
United States v. Wilson, 399 F.2d 459, 463 (4th Cir. 1968) : “There is enough doubt about a sociopath such as [defendant] to call for an exercise of the jury’s moral judgment. ...”
. Compare Campbell v. United States, 113 U.S.App.D.C. 260, 261, 307 F.2d 597, 598 (1962) :
As an administrative matter, “emotionally unstable personality” has
been regarded by the staff at St. Elizabeths as a mental disease only since November 1957.
. Blocker v. United States, 110 U.S.App.D.C. 41, 51, 288 F.2d 853, 863 (en banc 1961).
. Ten years ago Judge Burger said: “While the time span since 1954 is brief, our total study and collective case consideration of the problem is equal perhaps to as much as a half century of ease review of this problem in most jurisdictions.” Blocker v. United States, 110 U.S.App.D.C. at 52, 288 F.2d at 864 (en banc, 1961) (concurring opinion).
. A difference in language perception probably contributed to the development that psychiatric testimony concerning “product” causal relationship did not develop along the lines presaged by legal students of the problem. Early critiques in journals asserted that a but-for test of “product” would rarely, if ever, permit a psychiatrist to testify as to the existence of mental illness coexisting with a lack of “product” causal relationship to the crime, See, e. g., Wechsler, The Criteria of Criminal Responsibility, 22 U.Chi.L.Rev. 367, 371 (1955) ; De Grazia, The Distinction of Being Mad, 22 U.Chi.L.Rev. 339, 343 (1955). Presumably, the force of this analysis was strengthened when “mental disease or defect” was defined and tightened in McDonald. As events have developed, however, it has become almost commonplace that psychiatrists testifying as to the presence of mental disease have nevertheless found an absence of “product” causal relation with the crime, or at least expressed substantial doubt as to such relationship. Perhaps more to the point, it lias become commonplace for psychiatrists called by Government and defense to be in agreement on the mental disease aspects of their testimony and to differ on the issue of “product” relationship. This is not intended, in any way, as a criticism of any particular testimony. There is often a genuine and difficult question as to the relationship between a particular mental disease and particular offense. What is our concern, however, is that the inherent difficulty of this core problem has been intensified, and the sources of confusion compounded, by a kind of mystique that came to surround the “product” test, and testimony cast in that language.
. E. g., Hawkins v. United States, 114 U.S.App.D.C. 44, 310 F.2d 849 (1962) ; Isaac v. United States, 109 U.S.App.D.C. 34, 284 F.2d 168 (1960).
. This was also the suggestion of the National District Attorneys Association, subject to caveats, as the test recommended if the court did not accept its submission that the insanity defense should be abolished entirely.
. Compare New State Ice Co. v. Liebmann, 285 U.S. 262, 280, 52 S.Ct. 371, 76 L.Ed. 747 (1932) (dissenting opinion of Brandeis, J.).
. Amicus points out that in Freeman the Second Circuit referred to the fact that the Third and Tenth Circuits “have employed their own language approaching the objectives of the Model Penal Code formulation,” and then offered a discussion of guiding policy considerations, including Senator Dodd’s espousal of an approach sending “marginal” cases to a hospital rather than prison, that, as amicus puts it, “strikes quite a different tone than, say, the analogous discussion of the Tenth Circuit in Wion.”
. See, e. g., Report of President’s D.C. Crime Commission at pp. 550 if. A majority of the members of the Commission preferred the ALI rule, but were concerned lest depature from Durham-Me-Donald spawn confusion.
. “ [I] t may be that psychiatry and the other social and behavioral sciences cannot provide sufficient data relevant to a determination of criminal responsibility no matter what our rules of evidence are. If so, we may be forced to eliminate the insanity defense altogether, or refashion it in a way which is not tied so tightly to the medical model.” Washington v. United States, 129 U.S.App.D.C. at 42, n. 33, 390 F.2d at 457 (1967).
. It suggests that a mental condition be exculpatory solely as it negatives mens rea.
. E. g., Mr. Dempsey. To the same general effect is the position in the research memorandum from the University of Virginia Law School Research Group to Mr. Flynn, appellant’s appointed counsel attached to his brief.
. See e. g., Burger, then Circuit Judge, Proceedings of the Sixth Annual Meeting of the National Conference of State Trial Judges, Chicago, Illinois, Aug. 9-11, 1963, quoted in Wion v. United States, 325 F.2d at 428, n. 10; Bazelon, Chief Judge, in Washington v. United States, 129 U.S.App.D.C. at 42, n. 33, 390 F.2d at 457 (1967) ; Haynesworth, Chief Judge, in en banc opinion in United States v. Chandler, 393 F.2d at 928 (1968) ; see also remarks of Chief Justice Weintraub (of New Jersey) in Insanity as a Defense— Panel Discussion, Annual Judicial Conference, Second Circuit, 37 F.R.D. 365, 369 (1964).
. Davis v. United States, 160 U.S. 469, 484-485, 16 S.Ct. 353, 40 L.Ed. 499 (1895) ; Durham v. United States, supra, 94 U.S.App.D.C. at 242, 214 F.2d at 876.
. Amicus argues that penal systems can only survive so long as they “accord substantially with the popular estimate of the enormity of guilt,” citing 1 W. Lecky, History of the Rise and Influence of the Spirit of Rationalism in Europe 336-337 (1891).
. Citing Harris, Respect for Persons in Ethics and Society 129-130 (R. De George ed. 1966).
. In 1953 the British Royal Commission on Capital Punishment proposed:
[A person is not responsible for his unlawful act if] at the time of the act the accused was suffering from disease of the mind (or mental deficiency) to stioh a degree that he ought not to he held responsible.
. The minority, together with the Reporter for the Model Penal Code (Pro*987fessor Herbert Weclisler), proposed the following test of insanity:
A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect liis capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of law is so substantially impaired that he cannot justly be held responsible.
This proposal appears as alternative (a) to paragraph (1) of Model Penal Code § 4.01 (Tent. Draft No. 4, 1955) (emphasis added).
. See authorities cited supra, note 6.
. See, e. g., Szasz, Psychiatry, Ethics and the Criminal Law, 58 Colum.L.Rev. 183, 195 (1958) “[To] have a ‘psychopathic’ personality is only a more elegant way of expressing moral condemnation.” See also, Star, “The Public’s Ideas About Mental Illness” (National Opinion Research Center, 1955) ; H. Kalven and H. Zeisol, The American Jury 405 (1966).
. He proposes (Br. 78) an instruction with this crucial sentence: “It is up to you to decide whether defendant had such an abnormal mental condition, and if he did whether the imjrairment was substantial enough, and was so related to the commission of the crime, that he ought not be held responsible.” (Emphasis added.)
. A. Goldstein, The Insanity Defense 81-82 (1967).
. See H. Kalven and H. Zeisel, The American Jury (1966), passim, and particularly Chapters 5, 8, 12, 15 et seq. See also, Rifkind, Follow-up: The Jury, The Center Magazine 59, 64 (July, 1970).
. See e. g., the response of the Attorney General in Ramer v. United States, 390 F.2d 564, 575, n. 10 (9th Cir. en banc, 1968).
. See ch. 7, section III: The Mentally 111 Offender, subsection “Experience Under the Durham Rule,” at p. 534 ff of the Report, including Tables 1--10.
. McDonald was decided in 1962. For fiscal years ending June 30, 1964-1970, there were 21 verdicts of not guilty by reason of insanity in trials by jury, 265 such verdicts in trials by court. These data appear in Appendix C of Mr. Dempsey’s brief, as revised by submission of Sept. 21, 1971.
Mr. Dempsey provides data on all terminations for fiscal 1964-1968. The data for these five years show 7537 terminations, and 194 verdicts of not guilty by reason of insanity. The other terminations are: 3500 verdicts of guilty on plea, 1567 verdicts of guilty after trial, and 629 verdicts of not guilty.
. These trials are discussed in the amicus submission of David Chambers, consultant, who prepared a report on the John Howard Pavilion at St. Elizabeths Hospital, submitted to the Hospital and the National Institutes of Mental Health.
Professor Chambers characterizes most insanity trials to the courts as more *990nearly comparable to the taking of guilty pleas — consisting of a stipulated statement of facts; a conclusory Hospital report that the crime was the product of mental illness; and brief supporting testimony from a single John Howard psychiatrist — all in a context of a “tacit or explicit understanding” that the defendant will not contest his indefinite commitment to the Hospital.
. Any such analysis of the productivity testimony and verdicts not only would require prodigious time and effort, but might well be inconclusive in view of the, way experts testifying on the “product” issues come to diametric differences in the same trial.
. We do not share the cynical view that treats the instruction as devoid of consequence. In a study of the reactions of more than a thousand jurors to two experimental trials involving a defense of insanity, it was found that juries deliberated significantly longer when instructed under Durham than under M’Naghten. Yet this did not undercut consensus; there was no significant difference in the percentages of hung juries. R. Simon, The Jury and the Defense of Insanity 213 ff. (1967).
. See the opinion of Trask, J., for six of the 13 judges on the Ninth Circuit, in Wade v. United States, 426 F.2d 64, 75, 79.
. Mr. Dempsey is concerned lest the ALI test assigns responsibility unless capacity has been reduced “to the vagrant and trivial dimensions characteristic of the most severe afflictions of the mind,” see Wechsler, Codification of Criminal Law in the United States: The Model Penal Code, 68 Colum.L.Rev. 1425, 1443 (1968). But the application in fact will depend in the last analysis on the jury’s application of community standards to the evidence adduced.
. Even under McDonald the jury has frequently brought in a verdict of guilty, when the exculpatory rules would plainly permit, or even contemplate, a verdict of not guilty by reason of insanity. King v. United States, supra.
. Defendant is also exculpated if he lacks substantial capacity to appreciate the conduct is wrongful.
. In M’Naghten’s case, 10 Cl. & F. 200, 211, 8 Eng.Rep. 718, 722 (H.L.1843), the majority opinion of Lord Chief Justice Tindal ruled that the jury should be instructed in terms of the ability of the accused “to know that he was doing an act that was wrong,” adding: “If the question were to be put as to the knowledge of the accused solely and exclusively with reference to the law of the land, it might tend to confound the jury, by inducing them to be believe that an actual knowledge of the law of the land was essential in order to lead to a conviction.” When the question arose as to whether “wrong” means moral or legal wrong, the American courts split. One group, following M’Naghten, held the offender sane if he knew the act was prohibited by law. A second group, following the lead of Judge Cardozo in People v. Schmidt, 216 N.Y. 324, 110 N.E. 945, 948-950 (1915) ruled that, e. g., the defense was available to a defendant who knew the killing was legally wrong but thought it morally right because he was so ordered by God. The issue is discussed and authorities collected in A. Goldstein, The Insanity Defense, and notes thereto. In Sauer v. United States, 241 F.2d 640, 649 (9th Cir. 1957), Judge Barnes summed up the practicalities: “[The] practice has been to state merely the word ‘wrong’ and leave the decision for the jury. While not entirely condonable, such practice is explained in large measure by an awareness that the jury will eventually exercise a moral judgment ns to the sanity of the accused.”
This issue rarely arose under M’Naghten, and its substantiality was reduced if not removed by the control capacity test, since anyone under a delusion as to God’s mandate would presumably lack substantial capacity to conform his conduct to the requirements of the law.
We are not informed of any case where a mental illness left a person with capacity to appreciate wrongfulness but not a capacity to appreciate criminality. If such a case ever arises, supported by credible evidence, the court can then consider its correct disposition more meaningfully, in the light of a concrete record.
. See Comments to Fourth Draft, p. 160 :
6. Paragraph (2) of section 4.01 is designed to exclude from the concept of “mental disease or defect” the case of so-called “psychopathic personality.” The reason for the exclusion is that, as the Royal Commission put it, psychopathy “is a statistical abnormality; that is to say, the psychopath differs from a normal person only quantitatively or in degree, not qualitatively : and the diagnosis of psychopathic personality does not carry with it any explanation of the causes of the abnormality.” While it may not be feasible to formulate a definition of “disease,” there is much to be said for excluding a condition that is manifested only by the behavior phenomena that must, by hypothesis, be the result of disease for irresponsibility to be established. Although British psychiatrists had agreed, on the whole, that psychopathy should not be called “disease,” there is considerable difference of opinion on the point in the United States. Yet it does not seem useful to contemplate the litigation of what is essentially a matter of terminology; nor is it right to have the legal result rest upon the resolution of a dispute of this kind.
. We note that the Second Circuit adopted the caveat paragraph on the ground that
a contrary holding would reduce to absurdity a test designed to encourage full analysis of all psychiatric data and would exculpate those who knowingly and deliberately seek a life of crime.
(Freeman, 357 F.2d at 625).
. See, e. g., D. Abrahamsen, Who Are the Guilty? 125 (1952).
. Jenkins v. United States, 113 U.S.App.D.C. 300, 307 F.2d 637 (en banc, 1962) (assuming substantial experience in the diagnosis of disease in association with psychiatrists or neurologists).
. E. g., the opinions in Durham, Garter, McDonald and Washington, and Judge Burger’s concurring opinion in Blocker.
. Pope v. United States, 372 F.2d 710, 736 (8th Cir. 1967).
. The Association points out that “the effects of poverty, historical factors and prejudice may well have an adverse effect upon an individual’s mental condition.”
. By § 207(6) of the D.C. Court Reform and Criminal Procedure Act of 1970, P.L. 91-358.
. E. g., Bazelon, C. J., concurring in United States v. Eichberg, 142 U.S.App.D.C. 110, 114, 439 F.2d 620, 624 (1971), where the vitality of Leland v. Oregon, 343 U.S. 790, 72 S.Ct. 1002, 96 L.Ed. 1302 (1952) is questioned in view of In re Winship, 397 U.S. 358, 90 S.Ct. 1068, 25 L.Ed .2d 368 (1970).
See also Report of the President’s D.C. Crime Commission (1966) 553: “The majority of tlie. Commission also believes that the views of the dissenting justices in Leland v. Oregon are grounds for caution. * * * We believe that there is at least a substantial question whether requiring the defendant to prove insanity in a Federal court would be upheld by the Supreme Court.”
. United States v. Thompson, 147 U.S.App.D.C. 1, 452 F.2d 1333 (1971).
. In Bolton the Court relied in part on the circumstance that an acquittal by reason of insanity might reflect only a doubt as to sanity. This may be affected by the 1970 provision putting the trial burden on defendant to establish his insanity.
We are not addressing ourselves to the procedure that would result if a court concludes that § 301(d)(2) is unconstitutional.
. Our doctrine is different from the doctrine of “partial responsibility” that permits a jury to find that a defendant’s mental condition was such that he is only “partly responsible,” and therefore entitled to a verdict reducing the degree of the offense. See Model Penal Code, Comments to Art. 201, app. B at 111 (Tentative Draft No. 9, 1959), quoting the English Homicide Act of 1957, 5 & 6 Eliz. 2, c. 11.
. The term “malice” in second degree murder has been extended to include recklessness where defendant had awareness of a serious danger to life and displayed wanton disregard for human life. Lee v. United States, 72 App.D.C. 147, 150-151, 112 F.2d 40, 49-50 (1940) ; Austin v. United States, supra, 127 U.S.App-*999D.C. at 184, 382 F.2d at 133; United States v. Dixon, 135 U.S.App.D.C. 401, 405, 419 F.2d 288, 292 (1969) (concurring opinion).
. There was no independent consideration in Stewart v. United States, 129 U.S.App.D.C. 303, 394 F.2d 778 (1968), which was not an en banc court, and merely cited the earlier cases.
. People v. Nicolaus, 65 Cal.2d 866, 56 Cal.Rptr. 635, 423 P.2d 787 (1967) ; People v. Goedecke, 65 Cal.2d 850, 56 Cal.Rptr. 625, 423 P.2d 777 (1967) ; People v. Ford, 65 Cal.2d 41, 52 Cal.Rptr. 228, 416 P.2d 132 (1966) ; People v. Conley, 64 Cal.2d 310, 49 Cal.Rptr. 815, 411 P.2d 911 (1966) ; People v. Wolff, 61 Cal.2d 795, 40 Cal.Rptr. 271, 394 P.2d 959 (1964) ; People v. Gorshen, 51 Cal.2d 716, 336 P.2d 492 (1959) ; People v. Wells, 33 Cal.2d 330, 202 P.2d 53 (1949).
. Schwickrath v. People, 159 Colo. 390, 411 P.2d 961 (1966) ; Gallegos v. People, 159 Colo. 379, 411 P.2d 956 (1966) ; Becksted v. People, 133 Colo. 72, 292 P.2d 189 (1956) ; Battalino v. People, 118 Colo. 587, 199 P.2d 897 (1948) ; Ingles v. People, 92 Colo. 518, 22 P.2d 1109 (1933).
. State v. Di Paolo, 34 N.J. 279, 168 A.2d 401 (1961), clarified in State v. Sikora, 44 N.J. 453, 210 A.2d 193 (1965).
. State v. Gramenz, 256 Iowa 134, 126 N.W.26 285 (1964).
. State v. Nichols, 3 Ohio App.2d 182, 209 N.E.2d 750 (1965).
. State v. Clokey, 83 Idaho 322, 364 P.2d 159 (1961).
. State v. Donahue, 141 Conn. 656, 109 A.2d 364 (1954).
. Starkweather v. State, 167 Neb. 477, 93 N.W.2d 619 (1958).
. State v. Padilla, 66 N.M. 289, 347 P.2d 312 (1959).
. Fox v. State, 73 Nev. 241, 316 P.2d 924 (1957).
. New York, People v. Moran, 249 N.Y. 179, 163 N.E. 553 (1928) ; Rhode Island, State v. Fenik, 45 R.I. 309, 121 A. 218 (1923) ; Utah, State v. Green, 78 Utah 580, 6 P.2d 177 (1931) ; Wisconsin, Hempton v. State, 111 Wis. 127, 86 N.W. 596 (1901) and Wyoming, State v. Pressler, 16 Wyo. 214, 92 P. 806 (1907).
. Battalino v. People, 118 Colo. 587, 199 P.2d 897, 901 (1948).
. State v. Janovic, 101 Ariz. 203, 417 P.2d 527 (1966) ; Armstead v. State, 227 Md. 73, 175 A.2d 24 (1961) ; State v. Flint, 142 W.Va. 509, 96 S.E.2d 677 (1957) ; Ezzell v. State, 88 So.2d 280 (Fla.1956).
. 127 U.S.App.D.C. at 189-190, 382 F.2d at 138-139.
. See Belton v. United States, 127 U.S.App.D.C. 201, 203, 382 F.2d 150, 152 (1967).
. 78 Stat. 944 (1960), 21 D.C.Code § 501 et seq.
. Millard v. Harris, 132 U.S.App.D.C. 146, 150, 406 F.2d 964, 968 (1968).
. In re Alexander, 124 U.S.App.D.C. 352, 372 F.2d 925 (1967).
. Lake v. Cameron, 124 U.S.App.D.C. 264, 364 F.2d 657 (1966).
. S.Rep.No.925, 88th Cong., 2d Sess., 31 (1964).
. At the risk of repetition, but out of abundance of caution, and in order to obviate needless misunderstanding, we reiterate that this opinion retains the “abnormal mental condition” concept that marks the threshold of McDonald. Assuming the introduction of evidence showing “abnormal mental condition,” the judge will consider an appropriate instruction making it clear to the jury that even though defendant did not have an abnormal mental condition that absolves him of criminal responsibility, e. g., if he had substantial capacity to appreciate the wrongfulness of his act or to control his behavior he may have had a condition that negatives the specific mental state required for a higher degree of crime, e. g., if the abnormal mental condition existing at the time of the homicide deprived him of the capacity for the premeditation required for first degree murder.
To avoid needless confusion, we contemplate strict adherence to the term “abnormal mental condition,” and do not contemplate use of terms such as “mental unsoundness,” which might confuse a juror who considered that any defendant committing a wanton act is “unsound,” and, presumably, suffering from “mental unsoundness.”
Since the defense relates to a specific mental element of a crime, it is not applicable to “malice” established on an objective standard in a case of second degree murder (supra, note 53). Whether it may be applicable in a case where malice is established on a subjective standard, so ns to reduce the offense to manslaughter, is a matter that requires further analysis and reflection. The cases are in conflict, see Annot., 22 A.L.R.3d 1228 (1968). Generally, at least, a defendant with substantial capacity to appreciate the wrongfulness of his crime would appear to have the capacity requisite for malice. Without further study, however, we hesitate to rule as a matter of law concerning the possibility that there may be abnormal mental conditions falling short of legal insanity that would leave the defendant *1003with cajmcity to appreciate the wrongfulness of his acts, but without awareness of the clanger of serious harm. The problem is remitted to future consideration, which we think will be aided by the availability of a specific factual context.
. Compare Washington v. United States, 129 U.S.App.D.C. 29, 35, 390 F.2d 444, 450 (1967) : “[T]he persistent use of conclusory labels may have hindered the jury in getting to the underlying facts. But we think the jury obtained enough concrete information to preclude us from disturbing the verdict. The defense psychiatrists and, on cross-examination, the Government psychiatrists gave some meaningful descriptions of defendant’s mental and emotional processes. . . . [T]aken as a whole, the testimony in this case was, if anything, a little better than in most insanity cases. Under these circumstances, reversal seems inappropriate.”
. “Now, another one, you remember on the same test, that drawing test, the doctor said he had ten of those little things and they had squiggles and lines and angles, and he was asked to draw those, *1004ten of them separately. And the doctor said he rotated, he rotated one. And I said, well, what was the significance of that. Well, the significance is that shows that there is organic brain damage. That is a very hard indicator of organic brain damage. Why organic brain damage. He said he meant structural damage, something physically wrong with the brain, a part missing, a dead cell, something like that, a lesion in the brain.
“And I asked the doctor how many of them did he rotate, how many of them did he turn the picture a little bit. I asked him how many did he rotate 90 degrees, and I think he said it was, how many out of those ten — one. That is a hard indicator, that is a hard indicator of organic brain damage.
“Ladies and gentlemen, then we came to that ink blot, and the doctor said, well, the usual thing about that was those anatomical things, and how many of them were there. Well, let’s see, and he counts, and there are four. How. many responses. Fourteen of them. Fourteen responses and four of them turn out to be anatomical things — hearts or whatever it happened to be.
“Is there something unusual about that? Is a man crazy when he sees a heart or something else four times, four different anatomical things or maybe the same things in those little drawings, these little ink blots. And all, they are just blots of ink. Is a man crazy when he sees them? And how about that last one, that rocket one. He says he sees a rocket going off.
“I asked him doctor, was there any rocket fired during that period of time that might stick in a man’s brain and might suggest it to him. The doctor doesn't know. But there is something explosive about a personality if he sees a rocket on a little ink blot.
“Well, ladies and gentlemen, there is not much I can say about that; I am not an expert. You heard the expert on the stand and he testified about that.
“But I can say one thing: that it is a jury decision. It is your province. It is your function to take that evidence and weigh that evidence and decide whether what that doctor said as far as you are concerned made any sense at all.”
íj; V sfc
. In King v. United States, we pointed out (at 125 U.S.App.D.C. 325, 372 F.2d 390):
[T]he prosecutor persistently drummed into the jury — without evidentiary basis, and contrary to the uncontradieted testimony of the Government psychiatrists called by the defense — the assertion that organic [brain] damage was negatived by the failure to detect it by physical tests, and that psychological tests could not establish organic brain damage. . . .
. We are aware that other circuits, in adopting the ALI test of criminal responsibility, have made their decisions retrospective, see e. g., United States v. Tarrago, 398 F.2d 621 (2d Cir. en banc, 1968) giving retrospective effect to its decision in Freeman, cited supra. However, we think sound principles — applied in Stovall v. Denno, 388 U.S. 293, 296 ff., 87 S.Ct. 1967, 18 L.Ed.2d 1199 (1967) so as to give only prospective effect even to constitutional rights — lead to the conclusion that our adoption of the ALI test be prospective. We liken this opinion to our decisions adopting a rule in the exercise of our supervisory jurisdiction for prospective application, see e. g., United States v. Thomas, 146 U.S.App.D.C. 101, 449 F.2d 1177, 1187 (1971) ; Harris v. United States, 140 U.S.App.D.C. 21, 23, 433 F.2d 1127, 1129 (1970).
In Tarrago the Second Circuit noted that its retroactivity ruling concerned only two oases and hence involved no problem of “significant burden on administration of justice.” Our court would be confronted with a substantially different problem. The criminal appeals pipeline in our court, unlike other Federal courts, relates for the most part to common law crimes. While acquittals for insanity are only in a range of 40 per annum (supra, p. 989) almost 700 persons per year are sent to St. Elizabeths Hospital for psychiatric examination with a view towards the possibility of presenting an insanity defense. See data for 1968 and 1969 in Broderick, Involuntary Hospitalization for Mental Illness, 20 Catholic U.L.Rev. 564, n. 80.
More significantly, this opinion is not, like Freeman, a change in substantive law from outmoded doctrine retained for a long period without critical examination and modification. In this circuit, that kind of departure was wrought in Durham — which, incidentally, was made prospective. In this opinion we have acknowledged and retained the positive contribution of the 1954 decision in Durham (see p. 977, supra), relating legal doctrine to modern medical thinking, together with McDonald’s 1962 improvement in the judicial definition of mental disease and defect. The President’s Commission noted in 1966 (see supra, p. 990) that Durham-McDonald is not significantly different in substantive content from the ALI test. Although today we drop the term “product,” we retain the underlying concept of causal relationship. Our change helps cope with the problem of oversteering and lack of communication, but that problem had also been considered in the 1967 Washington opinion, prescribing a course for “future cases” (129 U.S.App.D.C. at 36, 390 F.2d at 451). Today's course is likewise for future trials.
While our change in formulation will, we think, be helpful to the jury, it does not require retrospective application as indispensable to integrity in the fact-finding process. As we have already pointed out, we did not adopt the new rule in the contemplation that it would affect a significant number of verdicts.
. Stovall v. Denno, 388 U.S. 293, 301, 87 S.Ct. 1967, 18 L.Ed.2d 1199 (1967).
. As to this judgment, the District Court may exercise its discretion to revise the sentence. The foregoing is without prejudice to an appeal from the judgment, if appellant be so advised, on the ground that it is not consistent with our opinion and mandate.
. The court will revise the third paragraph of the Washington Appendix (129 U.S.App.D.C. at 42, 390 F.2d at 457) to read:
As an expert witness, you may, if you wish and if you feel you can, give your opinion whether at the time of his conduct the defendant suffered from a mental disease or defect, and whether, as a result, defendant either lacked substantial capacity to appreciate the wrongfulness of his conduct, or lacked substantial capacity to conform his conduct to the requirements of the law. You may explain in terms of the development, adaptation and functioning of the defendant’s behavioral processes.
. 2 J. Stephen, History of the Criminal Law of England 128 (1883).
Note: In addition to this instruction, for submission of the insanity issue to the jury, the judge will have given the jury the guidance provided by reading in its presence the instruction to the expert witness required by Washington v. United States, 129 U.S.App.D.C. 29, 42, 390 F.2d 444, 457 (1967), revised in accordance with note 82 of the opinion in United States v. Brawner, 153 U.S.App.D.C. at-, 471 F.2d at 1006.