(dissenting) — The majority applies the principles of ER 402, 702, and 703 to the admissibility of expert testimony on a defendant’s diminished capacity. I agree with the majority these evidentiary principles for the general admission of expert testimony are appropriate. But the majority does not analyze the admissibility of the experts’ testimony here against time-honored principles of testimonial capacity for expert witnesses.
In addition, the majority also determines the test for diminished capacity set forth in State v. Edmon, 28 Wn. App. 98, 621 P.2d 1310 (1981), is no longer applicable. It would appear any type of expert testimony that negates a specific intent must be admitted under the majority’s analysis. This goes too far.
Under the circumstances of this case, the trial court carefully assessed the question of whether Ellis demonstrated a causal connection between his alleged mental disorders and the requisite ability to form the criminal intent. Consequently, the trial court did not abuse its discretion in excluding the defense expert testimony.
The language of psychology and the law is often incongruous. As a result, much confusion has arisen not only in Washington courts, but in courts around the country, regarding what has been termed the diminished capacity defense. Rather than illuminate this confusion the majority decision exacerbates it by eliminating the Edmon guidelines our courts have employed for more than 15 years to evaluate the admissibility of psychological evidence, without offering new guidance. Because I believe it unwise for us to embark on uncharted seas in this difficult area of the law, and because the trial court correctly decided the proffered *526testimony of two psychologists in this case was not relevant to any issue to be determined at trial, I dissent.
ANALYSIS
A. The Trial Court did not Err in Excluding the Experts’ Opinions
The facts of this case are egregious. Ellis and his mother were drinking and smoking marijuana and, allegedly because of the mother’s statement regarding Ellis’s girl friend, his personality disorders were engaged to such a degree that he beat her to death with a breadboard and then proceeded to beat his baby sister to death with the breadboard as well. The trial court, however, properly concluded the experts simply did not demonstrate that Ellis’s “disorders” rendered him incapable of intending the crime of which he was convicted.
Ellis is charged with aggravated murder in the first degree. To be guilty of this crime, a person must have caused the death of another with “a premeditated intent” to cause that death.94 RCW 9A.32.030(1)(a). Thus, not just intent, but “premeditated intent” is one of the elements of the crime the State must prove beyond a reasonable doubt in order for Ellis to be found guilty of the crime with which he is charged. State v. Crediford, 130 Wn.2d 747, 759, 927 P.2d 1129 (1996) (citing In re Winship, 397 U.S. 358, 363, 90 S. Ct. 1068, 1072, 25 L. Ed. 2d 368 (1970)). As we said in State v. Lane, 112 Wn.2d 464, 472-73, 771 P.2d 1150 (1989):
Premeditation is an element separate and distinct from the specific intent to kill required for first degree murder; it also distinguishes first degree murder from second degree murder. *527The failure of the State to sufficiently establish premeditation has been held to require reversal of a conviction for aggravated first degree murder. Clearly, therefore, premeditation constitutes an essential element of the crime of aggravated first degree murder.
(Footnotes omitted.)
WPIC 26.01.01 defines premeditation as follows:95
Premeditated means thought over beforehand. When a person, after any deliberation, forms an intent to take human life, the killing may follow immediately after the formation of the settled purpose and it will still be premeditated. Premeditation must involve more than a moment in point of time. The law requires some time, however long or short, in which a design to kill is deliberately formed.
We first approved this formulation in State v. Rice, 110 Wn.2d 577, 604, 757 P.2d 889 (1988), cert. denied, 491 U.S. 910, 109 S. Ct. 3200, 105 L. Ed. 2d 707 (1989), and more recently affirmed it in State v. Benn, 120 Wn.2d 631, 658 n.4, 845 P.2d 289, cert. denied, 510 U.S. 944, 114 S. Ct. 382, 126 L. Ed. 2d 331 (1993). The key considerations for the jury’s ultimate determination are (1) did Ellis form the intent to take human life, and (2) did he deliberately form a design to kill over some period of time longer than a moment.
1. The Experts Lacked Testimonial Knowledge
The right to present witnesses in one’s own defense is a fundamental element of due process of law. State v. Maupin, 128 Wn.2d 918, 924, 913 P.2d 808 (1996). It follows that one must be allowed to present witnesses to rebut or negate the State’s presentation of proof as to an element of the crime with which one is charged. Thus, if the State in this case, presents, as it must, some evidence to the jury to *528suggest premeditation by Ellis, he must have the right to present evidence to the contrary. To deny him this right would be to deny him a fundamental element of due process of law.
But the right to present evidence in one’s own defense is not utterly unfettered. That evidence must be relevant. There is no constitutional right to introduce irrelevant evidence. Maupin, 128 Wn.2d at 925; State v. Hudlow, 99 Wn.2d 1, 15, 659 P.2d 514 (1983). Accord United States v. Becker, 444 F.2d 510, 511 (4th Cir. 1971); People v. Grisset, 288 Ill. App. 3d 620, 681 N.E.2d 1010, 1019, 224 Ill. Dec. 389, appeal denied, 174 Ill. 2d 576, 686 N.E.2d 1167, 227 Ill. Dec. 11 (1997); O’Rourke v. State, 166 Neb. 866, 90 N.W.2d 820, 823 (1958); State v. Cardenas-Hernandez, 219 Wis. 2d 516, 579 N.W.2d 678, 687 (1998). At issue in this case is the relevance of the testimony of two psychologists to the jury’s task.
Both Dr. Whitehill and Dr. Cripe opined Ellis was not able to premeditate the murder of his mother and half-sister. Even though the question of premeditation is the ultimate and central fact for the jury to decide, Ellis argues persuasively he should be allowed to introduce this testimony at his trial as rebuttal to negate the premeditation element of the crime of which he is accused. Beginning in 1940, however, in a steady line of cases we have never questioned or overruled, we have held such testimony to be inadmissible because the experts lacked testimonial knowledge.
In State v. Davis, 6 Wn.2d 696, 108 P.2d 641 (1940), the defendant in a first degree murder case attempted to introduce the written report of an “expert alienist”96 who had examined the defendant in jail and had concluded the defendant had not premeditated the murder. The trial court disallowed the evidence, and we affirmed because “[t]he witness, of course, had no personal knowledge concerning the facts of the case, and his opinion on the question of *529premeditation or the lack of premeditation was inadmissible.” Id. at 707. Dr. Whitehill and Dr. Cripe likewise have no personal knowledge of the facts of the murders; they know only what Ellis told them and what is in the police reports.
In State v. Farley, 48 Wn.2d 11, 290 P.2d 987 (1955), cert. denied, 352 U.S. 858, 77 S. Ct. 79, 1 L. Ed. 2d 65 (1956), we explained the reasons for the personal knowledge requirement where the defendant attempted to present the testimony of a doctor regarding the defendant’s state of mind during a homicide:
The question involved in the concluding assignment of error was:
“Doctor, would you state whether or not you formed an opinion as to whether or not the specific reaction at the time of the killing was or was not an outbreak of rage and destructive hostility under severe stress?” (Emphasis added.)
It appears from the record that the doctor, whose qualifications are admitted, had examined appellant on three occasions while he was in custody, and had seen the reports of two other doctors’ examinations of appellant.
The purpose of the question here involved was not to elicit a diagnosis of appellant’s mental condition as revealed by the examinations. Counsel was trying to rebut the inference of premeditation and intent, which could be drawn from the circumstances of the killing, by having the doctor testify as to a fact with regard to specific mental reaction of appellant at the time he committed the crime. Since the doctor was not present at the murder, he had no testimonial knowledge of appellant’s appearance, statements, acts, and demeanor, or the circumstances surrounding the crime. His diagnosis of appellant’s state of mental health, as revealed by subsequent examinations, cannot be related to the particular instant of the crime. Nevertheless, counsel contend that, if a layman can express an opinion as to the mental condition of a defendant at the time of committing a crime, there is even more reason for permitting a doctor to do so. This contention misconceives the Washington rule. In State v. Gaul, 88 Wash. 295, 152 P. 1029[, 1032 (1915),] with regard to a layman’s testimony, we said:
*530“The intent with which an act is done is a mental process, and as such generally remains hidden within the mind where it is conceived, and is rarely, if ever, susceptible of proof by direct evidence, but may be inferred or gathered from the outward manifestations, by the words or acts of the person entertaining it, and the facts or circumstances surrounding or attendant upon the offense with which he is charged.”
Accordingly, a layman who sees the commission of a crime can describe the acts, the appearance, and demeanor of a defendant, from which inferences as to a defendant’s mental processes may be drawn, but a doctor who was not present at a crime has no testimonial knowledge of the circumstances needed to support such inferences.
Id. at 20-21 (emphasis omitted). Accord State v. Craig, 82 Wn.2d 777, 779-80, 514 P.2d 151 (1973) (“doctor who was not a witness to the crime and does not have firsthand knowledge of the defendant’s state of mind at the time, may not give his opinion as to what that mental state was”); State v. Moore, 61 Wn.2d 165, 172-73, 377 P.2d 456 (1963) (psychiatrist’s opinion that defendant was incapable of forming intent not sufficient to require a manslaughter instruction); State v. Cogswell, 54 Wn.2d 240, 248, 339 P.2d 465 (1959) (testimonial knowledge of demeanor of defendant at proximate time of offense required for admission of testimony as to defendant’s capacity to form specific intent); State v. Upton, 16 Wn. App. 195, 201, 556 P.2d 239 (1976) (doctor’s opinion regarding defendant’s mental state at the time of the shooting, absent testimonial knowledge, properly excluded), review denied, 88 Wn.2d 1007 (1977); State v. Fullen, 7 Wn. App. 369, 382-83, 499 P.2d 893, review denied, 81 Wn.2d 1006 (1972), cert. denied, 411 U.S. 985, 93 S. Ct. 2282, 36 L. Ed. 2d 962 (1973).97 Even hypothetical questions to a doctor as to a defendant’s state of mind at *531the time of an offense are barred under this rule. State v. Tyler, 77 Wn.2d 726, 759, 466 P.2d 120 (1970) (answers to hypothetical questions are “no more than conjecture and speculation”), vacated in part by 408 U.S. 937, 92 S. Ct. 2865, 33 L. Ed. 2d 756 (1972). This line of cases remains the law.98
As a rule of evidence, the testimonial knowledge requirement makes eminent good sense. It mirrors the common law rule that laypersons may opine on the mental responsibility of others providing they personally observed the facts to which they are testifying. Carr v. Deking, 52 Wn. App. 880, 886, 765 P.2d 40 (1988), review denied, 112 Wn.2d 1019 (1989).
Dr. Whitehill and Dr. Cripe do not have testimonial knowledge of the murders. For all they or anybody else knows, Ellis awakened the morning of the murders with the intent to murder his mother and sister that night. For all they or anybody else knows, Ellis attacked them with the breadboard without any provocation whatsoever, in furtherance of the murderous design he formed early that morning. The psychologists’ testimony as to Ellis’s state of mind at the time of the murders would be no more than conjecture and speculation.99 Under case law that has been on the books for nearly 50 years, the trial court properly excluded it.
*532Although on its face the proffered testimony seems precisely apropos to the question of premeditation, what is missing from this case and from the trial court’s analysis is the precise legal definition of premeditation. The psychologists spoke about premeditation in terms that evidently had some meaning to them from a diagnostic viewpoint, but no one asked them to apply their diagnoses to the meaning of premeditation under Washington law set forth above.
These legal questions of premeditation are vastly different from the aspects of Ellis’s behavior the psychologists testified about. The psychologists gave reasons stemming from psychodynamic factors to establish why Ellis did what he did, not whether he formed the intent to kill. They said he could not have premeditated because, according to what Ellis told them, he reacted on the spur of the moment, enraged by a derogatory remark his mother made about his girl friend.
But acting impulsively does not negate premeditation. *533The question is: did Ellis form the intent to kill his mother and then act on that intent after some, albeit brief, deliberation? The experts did not speak to Ellis’s intent, or the formation of a design to kill. They said only that he could not control his “rágefulness” because of his multiple personality disorders. These diagnostic conclusions do not answer the relevant legal question stemming from the legal definition of premeditation the jury will have to apply to the facts. That being the case, the trial court properly excluded the psychologists’ proffered testimony as being irrelevant.
2. The Experts’ Testimony was Inadmissible Under ER 702
Another reason for excluding the psychologists’ testimony is the ER 702 requirement that testimony by an expert, to be admissible, must be helpful to the jury:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
ER 702 permits expert testimony only if it will assist the trier of fact. Testimony that is confusing, arcane, or otherwise unintelligible100 will not assist the trier of fact. I *534cannot say the trial court abused its discretion in ruling such testimony inadmissible.
To the extent the testimony of Dr. Whitehill and Dr. Cripe did not address the question of premeditation from a legal point of view, but only from a psychological point of view, it could not possibly assist the jury in determining whether Ellis premeditated as a matter of law. An indication of the cross purposes between the testimony of the psychologists and the law occurred in the following colloquy:
Q. [The State] Dr. Cripe, how did Mr. Ellis’s mental disorder prevent him from forming premeditation that night? In other words, how did he pick up the breadboard without being able to intend what happened? . . .
A. What I am saying in the Ellis case here is, first of all, from everything that I can assess, I do not believe that this man went over there that night with the premeditated idea of killing his mother and his half-sister. I do not believe that at all. I think he went over there distressed. He went over there with his mental condition and disorder.[101]
This emerged into a series of moments of distress and stress stimuli that, given this defect of mind, he became overwhelmed and disorganized psychologically. And these actions that occurred, the grabbing of the breadboard, the hitting of the *535mother and later the sister, were not the result of beforehand thinking and intending to do those things. These were sort of automatically [102] driven by this breakdown of mind. And that’s where I am coming from.
Report of Proceedings at 51-52 (July 28, 1997). Dr. Cripe plainly believes Ellis can be found to have premeditated the murders only if he had planned them in advance of entering his mother’s abode. While such a belief may comport with a lay understanding of premeditation, it has little to do with the legal definition of premeditation, especially as applied to the facts of this case.
It may be correct that Ellis did not plan to kill his mother before he called on her (although the experts report this only because that is what Ellis told them). That does not mean he did not premeditate her death, however. Premeditation can occur in a variety of circumstances where hardly any deliberation occurs. See State v. Gentry, 125 Wn.2d 570, 598-99, 888 P.2d 1105 (1995) (describing such cases). Because Dr. Cripe did not address premeditation as it is defined in Washington law, his testimony about premeditation is therefore irrelevant and would not assist the jury. Dr. Whitehill’s testimony illustrates the same point:
Q. [The State] Would you agree that the homicides in this case were impulsive in nature?
A. [Dr. Whitehill] Yes, in that they happened suddenly and were not planned, and were very rapid. . . .
Q. Do you believe that [Ellis] has impulse control disorders; is that correct?
A. Yes, I do.
Q. All right. And the result of that is he has great difficulty, *536if not impossible, for him to control impulses under certain circumstances?
A. That’s right.
Q. It’s essentially very difficult for him to resist these impulses.
A. We certainly would say that clinically, whether or not it fits exactly your definition of that I am not real certain of, but we are talking about someone who under certain situations will act very rapidly without thought, and very extremely driven by abnormal levels of emotion, and with abnormal control mechanism, that is sort of what we are talking about here.
Report of Proceedings at 70-72 (June 16,1997). Once again, the testimony focused on Ellis’s inability to control himself, not on the central question of premeditation, i.e., whether he intended to take a human life and whether he deliberately formed a design to kill over some period of time longer than a moment. That Ellis exploded with anger over the remark his mother made about his girl friend, and this explosion was a manifestation of a mental defect, do not preclude the possibility that when the anger washed over him he did indeed deliberately form the design to kill his mother.
Dr. Whitehill wrote: “To believe that Mr. Ellis premeditated the deaths of his mother and sister is to believe, as per WPIC 26.01.01, that he thought these events over beforehand, which is to say, that he deliberated and formed the intent to take their lives.” Clerk’s Papers at 51. Here, Dr. Whitehill, like Dr. Cripe, seems to be relying on a lay definition of premeditation as a planning process that takes place well before the commission of a crime. As noted above, however, that is not the definition Washington law applies to premeditation. A brief, but discrete, instant of deliberation suffices for premeditation.
Perhaps the best illustration of the incongruity between the meaning of premeditation in Washington law and the concept of premeditation as the psychologists have used it *537in this case is the following excerpt from Dr. Cripe’s declaration:
In the Edmon case and in Mr. Ellis’ case, the State and their expert Dr. Gagliardi appear to be promoting an unrealistic absolutistic view regarding diminished capacity. They would like us to believe that unless a person had “no capacity” to form an intent, then the requirement of the law is not met. Their interpretation in this matter seems extreme and ultra conservative. I am convinced that with their view only a person in a coma or dead would lack the ability to form the intent of an action.[103] With their interpretation of diminished capacity, they would have argued that Mr. Edmon did not have any problem with intent and the doctor’s testimony regarding Mr. Edmon’s mental condition should be withheld from the trier of fact. I am convinced that with such a conservative stance, if Dr. Gagliardi had seen Mr. Edmon, he would have concluded that there was no basis for diminished capacity. After all, Edmon carried out “purposeful goal-directed” behaviors. He got up and went to work. He deliberately put a loaded gun on his person. He was able to direct specific punches at his boss. He was able to pull a gun out and pull the trigger while aiming at the target (the boss). All of these actions appear as goal directed and purposeful to an onlooker. Edmon was not psychotic. He knew where he was and what he was doing. He was “just” depressed and stressed. This kind of thinking only focuses upon the acts and does not consider the mental condition or state of the person before and during the actions.
In reality, although Edmon engaged in actions that appeared goal directed, the behavior all occurred in the context of a mental disorder (although not of psychotic proportions) and alcohol effects which were adversely affecting his perception, reasoning, emotion, judgment, decisions, and that ultimately resulted in his actions. His capacity to control and regulate he [sic] actions in a manner normally expected of a rational person with normal mind was adversely affected and eroded by his mental problems. This mental state diminished his capacity to rationally understand the situation, logically plan, make normal judgments and control emotion. In sum, because *538of his mental condition, he had a diminished ability to form a specific intent.
Clerk’s Papers 60-61. Earnestly, eloquently, and in evident good faith, Dr. Cripe has here set forth precisely why his testimony is not relevant to the ultimate determination of Ellis’s guilt for the premeditated murders of his mother and half-sister. As is evident, the final sentence is a non sequitur: Dr. Cripe fails utterly to say how Edmon’s diminished ability “to rationally understand the situation, logically plan, make normal judgments and control emotion” related to his capacity to intend to kill his boss. Edmon certainly exercised poor judgment because of the various psychological and emotional factors besetting him, but he also certainly intended to do what he did, i.e., kill his boss.
Likewise, Dr. Cripe sets forth his psychological diagnoses as the reasons why Ellis killed, then attempts to leap across a vast logical chasm to equate these reasons with Ellis’s purported inability to premeditate the deaths. He gives no reasons why the diagnosed disorders prevented Ellis from premeditating. If anything, the circumstances Dr. Cripe considered support premeditation, rather than negate it. Surely when Ellis’s mother made the remark that angered Ellis, the thought went through his mind, however explosively or uncontrollably, “That is the last straw. I will kill her.” He surely then formed the design to move to the breadboard, take it from its place, move back to his mother, and strike her with it, not once but several times. If he had not intended to kill his mother, she might still be alive. That his psychologists believe Ellis could not control his urge to kill his mother is not the same thing as saying he did not intend to do it. The psychologists offered no evidence that Ellis’s volitional difficulties negated his mental state; they simply asserted as much in a conclusory fashion. Their testimony fails the relevance test because it simply does not address—in legal terms—the question of whether Ellis premeditated the deaths.
Dr. Cripe evidently believes Ellis is less morally respon*539sible for the murders than some paradigmatic killer not beset with the same array of disorders who kills because he is evil. But a cold-blooded killer, say, for instance, someone who kills solely for money, might be diagnosed as having a severe Antisocial Personality Disorder. These are people we used to refer to as psychopaths or sociopaths. American Psychiatric Ass’n, Diagnostic and Statistical Manual of Mental Disorders [DSM-IV] 645 (4th ed. 1994). Such people have a pervasive pattern of disregard for and violation of the rights of others, as evidenced by repeated acts that subject them to arrest—deceitfulness, impulsivity, irritability and aggressiveness, reckless disregard for the safety of others, consistent irresponsibility, and “lack of remorse, as indicated by being indifferent to or rationalizing having hurt, mistreated, or stolen from another.” DSM-IV at 649-50. Perhaps Dr. Cripe would diagnose such a person as having severe Antisocial Personality Disorder, and conclude he could not have formed the specific intent to commit murder because he could not feel remorse and was deceitful and impulsive. Again, this last sentence is a non sequitur. The legal question is, did the accused premeditate, not did his personality disorders keep him from feeling remorse.
Dr. Cripe’s reports give further evidence his conclusions are based solely on his psychological diagnoses and his belief that Ellis’s mental condition should be considered in mitigation of his punishment, as opposed to bearing on the legal ramifications as they relate to Ellis’s guilt:
The homicides were impulsive. There is no evidence that Mr. Ellis planned all of this.[104] While he and his mother were under the influence of drugs and alcohol, he was significantly stressed by being put down by his estranged mother. He was instantly flooded with angry emotion, a cauldron of stored up aggression was released, and he lost control. He impulsively grabbed an unlikely weapon, a bread board, and bludgeoned his mother to death. The fact that he was putting on his shoes *540to leave, heard his sister stirring, and suddenly turned on her is another indication of an impulsive and unplanned act.[105] These homicides are the result of very complicated and powerful psychological and interpersonal factors which developed over many years, but were suddenly impulsively unleashed while in an intoxicated state. There are mitigating factors in this case. . . .
There is no question that Mr. Ellis’ problems are deep, longstanding, and resistant to change, and because of this he cannot be trusted to be loose in the community, but his extreme actions were the result of complicated forces and not an act of normal free will. The regrettable homicide behavior is the result of complicated interpersonal and psychological factors rather than a simple act of deliberate free will.[106] All involved, Mr. Ellis, his mother, and his sister are best seen as unfortunate victims of a most regrettable dysfunctional situation. I urge all concerned to think about these matters carefully before making final judgments.
Clerk’s Papers at 63. These thoughts belong to mitigation considerations, not considerations of guilt.
Finally, the majority opinion suggests any deficiencies in the psychologists’ testimony would be subject to cross-examination and therefore curable. I would not so lightly eliminate the trial judge’s function as arbiter of the rules of evidence. We surely would not permit someone to testify about Ellis’s mental state without some certification of his or her credentials as an expert on mental health, even though cross-examination would expose the lack of credentials. Only relevant, competent, and not unduly prejudicial evidence is admissible. The trial court has a gatekeeping function under the rules of evidence. Sometimes admis*541sibility questions are close. Nevertheless, we must not abdicate our gatekeeping role by receding from difficult decisions and letting the jury decide how much weight to give to evidence that is in fact irrelevant. The trial court must have the authority to exclude irrelevant evidence, as the trial court did here.
In summary, the trial court did not err in excluding the expert testimony. The testimony of Drs. Cripe and White-hill neither would help the jury nor would be relevant to the central issue of premeditation in this case. At best, the testimony was conclusory and speculative. The trial court read the psychologists’ reports, their declarations, and heard their testimony. We entrust the admissibility of expert testimony on diminished capacity to the discretion of the trial court, and overturn such decisions only upon a demonstration of abuse of discretion. State v. Hamlet, 133 Wn.2d 314, 324, 944 P.2d 1026 (1997). Such an abuse of discretion is present only when no reasonable person would take the view adopted by the trial court. State v. Castellanos, 132 Wn.2d 94, 97, 935 P.2d 1353 (1997). There was no abuse of discretion here.
B. Diminished Capacity Under Washington Law
Although I conclude the testimony of Ellis’s two experts on diminished capacity was inadmissible and Ellis therefore failed to establish diminished capacity, as our cases have described it, I feel compelled to discuss the doctrine of diminished capacity under Washington law in light of the majority’s resolve to abandon the Edmon guidelines.
The concept of diminished capacity was introduced into Washington law without discussion or debate in a five-page opinion in 1973. In State v. Ferrick, 81 Wn.2d 942, 944, 506 P.2d 860 (1973), we baldly stated, “The presence of a mental condition not amounting to criminal insanity is relevant to the elements or degrees of certain crimes involving specific *542intent.” We cited as authority a New York case,107 a New Jersey case,108 a California case,109 and an earlier case of our own, State v. White, 60 Wn.2d 551, 588, 374 P.2d 942 (1962), where we said as obiter dictum,
The presence of a mental disease or defect which falls short of criminal insanity may well be relevant to issues involving the elements or degrees of certain crimes, e.g., where malice, premeditation or intent are in issue.
In most recent diminished capacity cases, Washington courts have indicated such evidence may be admissible if an expert testifies a defendant suffers from a mental condition that impaired the defendant’s ability to form the requisite specific intent of a crime. State v. Eakins, 127 Wn.2d 490, 502, 902 P.2d 1236 (1995). Historically, our courts have been reluctant to admit all expert opinion on diminished capacity. The Edmon court, for example, specifically held that expert opinion that amounts to nothing more than testimony the defendant was emotional or had engaged in impulsive behavior would not constitute evidence of diminished capacity. Edmon, 28 Wn. App. at 105. Moreover, we have held the evidence of the mental condition to which the expert is testifying must be “substantial” and the evidence must “logically and reasonably connect the defendant’s alleged mental condition with the inability to possess the required level of culpability to commit the crime charged.” State v. Griffin, 100 Wn.2d 417, 419, 670 P.2d 265 (1983); State v. Ferrick, 81 Wn.2d 942; State v. Martin, 14 Wn. App. 74, 538 P.2d 873 (1975); State v. Carter, 5 Wn. App. 802, 490 P.2d 1346 (1971).
The peremptory announcement of the new diminished *543capacity rule in Ferrick is puzzling, given our earlier observation that “the legislature has established a policy in this state that only the most extreme degree of insanity will relieve a defendant of criminal liability. Any arguments for change in policy should, therefore, be addressed to the legislature.” White, 60 Wn.2d at 589. We not only failed to defer to the traditional and quintessential legislative prerogative to prescribe the rules for crime and punishment when we adopted diminished capacity in Ferrick, we did so without judicial discussion or debate on the necessity for or desirability of the rule as a matter of public policy. Cf. State v. Wilcox, 70 Ohio St. 2d 182, 436 N.E.2d 523, 525 (1982) (“The diminished capacity defense developed as a covert judicial response to perceived inequities in the criminal law.”). No debate in our cases has appeared since, and Ferrick remains the law. See, e.g., State v. Warden, 133 Wn.2d 559, 563, 947 P.2d 708 (1997) (“Diminished capacity is a mental condition not amounting to insanity which prevents the defendant from possessing the requisite mental state necessary to commit the crime charged.”).
In the meantime, however, California, which had pioneered the concept of diminished capacity, abolished the diminished capacity defense by statute in 1981, Cal. Penal Code § 28, and statutorily prohibits testimony by an expert as to a defendant’s mental state required for the crime charged. Cal. Penal Code § 29.110 See People v. Saille, 54 Cal. 3d 1103, 820 P.2d 588, 2 Cal. Rptr. 2d 364 (1991) (discussing history of diminished capacity defense in Cali*544fornia and the origins of the legislation abolishing it). Other states in powerful and persuasive opinions have rejected diminished capacity as well. See, e.g., State v. Bouwman, 328 N.W.2d 703 (Minn. 1982) (psychiatric testimony inadmissible as to premeditation); State v. Wilcox, 70 Ohio St. 2d 182, 436 N.E.2d 523 (1982); Stamper v. Commonwealth, 228 Va. 707, 324 S.E.2d 682, 688 (1985) (evidence of mental state at time of offense, in absence of an insanity defense, irrelevant).
One court criticized the diminished capacity defense in the following way: “[T]he more brutal, bizarre, or sensational the crime, the greater is the likelihood of a successful diminished capacity defense. ... In other words, the commission of the offense in most instances becomes ipso facto evidence of diminished capacity.” State v. Wilcox, 436 N.E.2d at 532. That is precisely what the proffered testimony in this case indicates. In assessing Ellis’s mental condition, Dr. Whitehill in part used the evidence of the murders to conclude Ellis was disturbed:
The level of violence in this crime is such as to bolster my contention that what we have is severe emotional discontrol as a manifestation of the borderline aspect of his personality disorder, not as a state of anger or rage; there certainly was rage, but not rage standing apart from mental disorder, rage as a component of an intense and impulsive reaction to his internal process, his borderline personality.
*545Report of Proceedings at 42-43 (June 16, 1997).111 Dr. Whitehill reverse-engineered the psychology in this case to conclude that because Ellis committed violent homicides he suffers from “severe emotional discontrol.” Dr. Cripe did the same thing:
It is very unusual that even persons with severe antisocial disorders kill their own parents, especially their mothers. Such extreme actions are often associated with an abnormal loss of control that is the result of a complicated mental/physical abuse history, chemical abuse/intoxication, and a stressful stimulus situation.
Clerk’s Papers at 64.112 In Dr. Cripe’s view, one has to be afflicted with really serious problems to kill one’s mother; therefore, Ellis must have serious enough problems to preclude his capacity to premeditate. In Fisher v. United States, 149 F.2d 28, 29 (D.C. Cir. 1945), aff’d, 328 U.S. 463, 66 S. Ct. 1318, 90 L. Ed. 1382 (1946), overruled by United States v. Brawner, 471 F.2d 969 (D.C. Cir. 1972), after the defendant introduced the testimony of a psychiatrist to the effect he was a “psychopathic personality of the predominantly aggressive type of behavior, and with an apathetic reaction to emotional situations,” the defendant asked the *546trial court to issue an instruction allowing the jury to take into account the defendant’s “entire personality” in considering the question of premeditation. The trial court refused to give the instruction and the Court of Appeals upheld the ruling, noting:
But it is obvious that brutal murders are not committed by normal people. To give an instruction like the above is to 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.
Fisher, 149 F.2d at 29. The proffered testimony of the psychologists in this case is subject to the same deficiency. The fatal deficiency, of course, is that while such testimony describes what impelled the defendant’s criminal act, it says nothing about whether the defendant was able to premeditate his actions once his psychology impelled him to act.
An additional reason to question the diminished capacity defense is that unconscious mental states as causes of criminal behavior do not necessarily translate into compulsions to commit criminal behavior. “To be caused to act by one’s character, one’s environment, or one’s synaptic firing patterns is not to be compelled to act. . . . One must point to something other than causation to make out the excuse of compulsion.” Michael S. Moore, Responsibility and the Unconscious, 53 S. Cal. L. Rev. 1563, 1642, 1665 (1980). Dr. Whitehill made precisely this point when he testified: “It wasn’t only that Mr. Ellis was in a rage, because people get in rages all the time without killing their mother, or two year old half sister.” Report of Proceedings at 31 (June 16, 1997). The core question is, to what level of moral and legal culpability do the people of Washington hold Ellis for failing to restrain himself when he experienced rage. This question is not susceptible to being answered by science.113 It is a question for a jury.
*547Ellis does not claim he did not know it was wrong to murder his mother and sister. He does not claim he committed the killings on orders from space aliens or disembodied spirits. He does not raise an insanity defense. He claims only that he is less culpable, i.e., can be guilty only of second degree murder rather than first degree murder, because his mental disorder prevented him from premeditating.114 But society has not yet decided to hold one less responsible for an act simply because a psychologist may have discovered the cause of the act.
A third problem with diminished capacity not amounting to insanity is the universality of its application. If Ellis is less responsible for his actions because of his unconscious mental state, then everyone is always excused. The concept of moral responsibility vanishes. We are all slaves to our unconscious and are therefore not fully responsible for anything we might do that is criminal or otherwise socially unacceptable. “The strongest conceptual objection to the use of psychodynamic explanations to reduce responsibility is that these explanations lead to the conclusion that no one is responsible.” Stephen J. Morse, Failed Explanations and Criminal Responsibility: Experts and the Unconscious, 68 Va. L. Rev. 971, 1036 (1982). This reductio argument is both inescapable and contrary to hundreds of years of English and American criminal law:
Few persons have not suffered from such emotions or problems as depression, frustration, thought disorder and fury, and most persons have occasionally wished, often intensely, to harm others or to behave lawlessly. Moreover, all persons differ in their cognitive and control capacities. But a person who knows what he or she is doing and has sufficient control to be legally responsible at all should be fully accountable for his or her conduct. Our expectation in a civilized society is that all of *548us will control ourselves, obey the law, and not harm others because of our moods and furies, no matter how intense or sustained they may be. ... It is not unjust to hold fully responsible those whose choices may be hard, but who are legally sane. If they know what they are doing and offend, they should be convicted and punished without reduction in the degree of offense or punishment.
Stephen J. Morse, Diminished Capacity: A Moral and Legal Conundrum, 2 Int’l J. Law & Psychiatry 271, 296-97 (1979).
Perhaps the clearest exposition of the problem with employing psychiatric testimony to assist the trier of fact in determining guilt (but not mitigation) is this:
Psychiatry and the law stand in essential contradiction or opposition. The legal view of behavior is in essence moralistic; an action is approved or disapproved, right or wrong, acceptable or unacceptable. A person is guilty or innocent as more or less clearly defined in advance by law. But psychiatry is a brand of medicine, and in medicine nothing is wrong, only sick. A man can be no more guilty of crime than he is guilty of an abscess.
Limiting the Insanity Defense: Hearings Before the Senate Subcomm. on Criminal Law, 97th Cong., 2d Sess. 172 (1982). The most acute example of the essential dissonance in discourse between mental health professionals and the law appears in Dr. Cripe’s bloodless description of the murders as “regrettable homicide behavior.” Clerk’s Papers at 63. This is Dr. Cripe appropriately speaking in his professional capacity as a diagnostician: what Ellis did was a “behavior,” albeit regrettable because it involved homicides. Such testimony does nothing to inform the ultimate moral and legal judgment the jury must make.
Society may one day conclude there should be a diminished level of responsibility for criminal acts related to mental disorders not amounting to insanity. The Washington Legislature has yet to make such a decision, however. In fact, the Washington Legislature has indicated it may be rather disinclined to adopt psychological or psychiatric evaluations as justifications for diminished responsibility. *549Although the Legislature has never recognized diminished capacity with regard to culpability, it has provided circumstances under which a court may depart from sentencing guidelines in the Sentencing Reform Act of 1981. RCW 9.94A.390. Among the list of mitigating circumstances justifying a downward departure from the sentencing guidelines is the following: “The defendant’s capacity to appreciate the wrongfulness of his or her conduct or to conform his or her conduct to the requirements of the law, was significantly impaired (voluntary use of drugs or alcohol is excluded).” RCW 9.94A.390(1)(e). This wording is nearly identical to the American Law Institute’s Model Penal Code definition 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 he lacks substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of law.
2 Charles E. Torcia, Wharton’s Criminal Law § 103, at 28 (15th ed. 1994). Thus, one of the criteria for obtaining mitigation in sentencing in Washington amounts to proving insanity under the Model Penal Code.
CONCLUSION
The trial court did not abuse its discretion in excluding the testimony of Ellis’s experts. Further, it is past time for us to reconsider the role.of diminished capacity in Washington law. We should abolish diminished capacity as a doctrine for negating the presence of intent in a criminal case, except in those instances where objective measures of incapacity, such as for intoxication, are present. The Legislature created an insanity defense to criminal conduct in RCW 10.77. It has not seen fit to create a diminished capacity exception to culpability. Instead, the Legislature installed mental state as a mitigating factor in criminal sentencing. Until the Legislature specifically adopts *550diminished capacity as a defense to criminal culpability, we should not do so by judicial fiat.
There is some confusion in the defense theory, stemming from some imprecise language in the experts’ reports and testimony, as to whether Ellis’s alleged diminished capacity prevented him from premeditating the crime, or having any intent whatsoever to commit the crime. As Ellis does not claim he is insane within the meaning of RCW 10.77, it would appear his theory is actually that he was unable to premeditate the murders of his mother and sister, and therefore cannot be guilty of aggravated murder in the first degree.
The verb premeditate “encompasses the mental process of thinking beforehand, deliberation, reflection, weighing or reasoning for a period of time, however short.” State v. Brooks, 97 Wn.2d 873, 876, 651 P.2d 217 (1982) (emphasis added). This has been the law in Washington at least since State v. Rutten, 13 Wash. 203, 212, 43 P. 30 (1895).
“Alienist” is an old term for psychiatrist.
I can find only one case to the contrary. In State v. Crenshaw, 27 Wn. App. 326, 333, 617 P.2d 1041 (1980), aff’d, 98 Wn.2d 789, 659 P.2d 488 (1983), the Court of Appeals said: “Fsychiatric opinion evidence regarding a defendant’s mental condition at a particular point in time is admissible when relevant to the question of a defendant’s sanity even though the expert witness did not personally observe the defendant at the time of the offense.” The only authority the *531court cited was Upton. The opinion was evidently simply mistaken in its reading of Upton, as the court in that case did in fact require testimonial knowledge.
Although the Court of Appeals in State v. Edmon, 28 Wn. App. 98, 621 P.2d 1310 (1981), attempted to set forth a compendium of foundation requirements for evidence about the mental state of a defendant, the opinion failed to mention the testimonial knowledge requirement, even though the Court of Appeals cited to Craig, Tyler, Moore, Cogswell, and Upton for other holdings. Edmon, 28 Wn. App. at 102-03.
Arguably, Ellis’s recitation of the facts of the murders to the psychologists is inadmissible hearsay. All that is in the record about the events of the homicide comes from the testimony and reports of the two psychologists. There were no witnesses to the murders other than Ellis. Everything the psychologists know about Ellis’s actions comes primarily from what Ellis told them. Thus, to admit the psychologists’ testimony of the events of the homicide, as Ellis told those events to them, is to admit hearsay.
Usually, hearsay for the purposes of medical diagnosis or treatment is admissible as an exception to the hearsay rule. EK 803(a)(4) provides:
*532Statements made for purposes of medical diagnosis or treatment and describing medical history, or past or present symptoms, pain, or sensations, or the inception or general character of the cause or external source thereof insofar as reasonably pertinent to diagnosis or treatment.
Thus, the psychologists’ description of the events surrounding the murders, as Ellis related those events, would be admissible as substantive evidence to prove the truth of the matter asserted, as what Ellis said can be taken as statements made for the purpose of diagnosis. The justification for this hearsay exception is the presumption the patient has a strong motivation to be truthful in giving information related to treatment or diagnosis.
Precisely the opposite is present here, however. Ellis’s motivation is to describe a situation in which his mental state would negate the State’s evidence of premeditation. In fact, because he has admitted committing the murders, the only defense he can possibly present to the first degree murder charge is lack of premeditation. Thus, the usual index of reliability justifying hearsay testimony of medical personnel is entirely absent in this case. If anything, what Ellis told the psychologists about the events of the murders has a high index of unreliability. In the words of one of the leading treatises on evidence:
[Statements [made for purposes of medical diagnosis] may be extremely unreliable as evidence of the facts related, since the condition for which the patient is consulting the psychiatrist may have impaired the patient’s perception, memory or veracity.
5 Jack B. Weinstein & Margaret A. Berger, Weinstein’s Federal Evidence § 803.09[8], at 803-47 (Joseph M. McLaughlin ed., 2d ed. 1998).
Examples of such testimony follow:
So we have an individual whose perceptional process, whose interpreting process, his decision making capacity and his abiliiy to properly regulate his behavior, was [sic] severely compromised as a direct result of this ongoing personality disturbance, severe in nature, and quite uncooling.
Report of Proceedings at 52-53 (June 16, 1997) (Dr. Whitehill).
We are talking about extreme pathology here, and breakdowns of mental observations that are not just an overreaction. We are talking about defects of mental functioning. I thought of it this way: Perhaps this would be useful to understand where I am coming from on this. We all sort of have little buttons on us, little red buttons, and if someone comes over and pushes it they can set us off, and get certain reactions. But as we grow and develop and your mind sort of develops, we sort of learn how to work around those, and control those through the powers of mind.
We are not talking about a little button. We are talking about a big button here, a button that is just the result of unspeakable things. And if this man *534gets into certain situations, and that big abnormal button gets pushed, you get big abnormal behavior. And so I don’t think it’s a fair characterization to speak of it as just a reaction. We are talking about an aberrant psychology.
Report of Proceedings at 73-74 (June 16, 1997) (Dr. Cripe).
Q. [The State] Now, tell us, please, what symptoms exactly were manifested when Mr. Ellis killed.
A. [Dr. Whitehill] Well, one dimension of the borderline adaptation, his intention on remitting emotionality unregulated in nature.
Q. So emotionality, intention.
A. Intention.
Q. Unregulated. Any others?
A. Impulsivity with respect to behavioral regulation.
Report of Proceedings at 55 (June 16, 1997).
Dr. Cripe’s knowledge of what happened the evening of the murders comes from Ellis’s self-report of how he felt and what he did.
The suggestion of automatism appears also in Dr. Cripe’s written report of August 7, 1996, where he said Ellis’s “extreme actions were the result of complicated forces and not an act of normal free will.” Clerk’s Papers at 63. Neither Dr. Cripe nor Dr. Whitehill has formally diagnosed Ellis as having been an automaton when he killed his mother and half-sister, and Ellis has not raised automatism as a defense.
Dr. Cripe here is evidently expressing his disagreement with the legal standard for either intent or premeditation. He is entitled to his opinion.
Here again Dr. Cripe indicates he has not focused upon the legal definition of premeditation, but has instead considered it only in the lay sense of having planned something well in advance.
Dr. Cripe continues to display the incongruity of his testimony about Ellis’s mental state with the legal question of premeditation. Ellis surely had more time to premeditate the killing of his half-sister than of his mother. Even from his own description of his actions to his psychologists, he had time to deliberate before picking up the breadboard once again and killing his little half-sister.
The reference to “free will” is confusing. Ellis has not claimed he was acting as an automaton, yet the essence of the testimony of both psychologists is that Ellis had no control of himself, and for that reason ought not be held responsible for murder in the first degree.
People v. Moran, 249 N.Y. 179, 163 N.E. 553 (1928). This was a case involving feebleness of mind rather than a personality or emotional disorder. It offers only tangential support for the holding in Ferrick, where the defendant claimed a mental disease.
State v. DiPaolo, 34 N.J. 279, 168 A.2d 401 (1961).
People v. Wells, 33 Cal. 2d 330, 202 P.2d 53, cert. denied, 338 U.S. 836, 70 S. Ct. 43, 94 L. Ed. 510 (1949).
California Penal Code § 28 reads, in part:
(a) Evidence of mental disease, mental defect, or mental disorder shall not he admitted to show or negate the capacity to form any mental state, including, but not limited to, purpose, intent, knowledge, premeditation, deliberation, or malice aforethought, with which the accused committed the act. Evidence of mental disease, mental defect, or mental disorder is admissible solely on the issue of whether or not the accused actually formed a required specific intent, premeditated, deliberated, or harbored malice aforethought, when a specific intent crime is charged.
(b) As a matter of public policy there shall be no defense of diminished capacity, diminished responsibility, or irresistible impulse in a criminal action or juvenile adjudication hearing.
*544(Emphasis added.) Two commentators on the California legislation noted:
The Legislature heard ample and scientifically sound expert testimony that convinced it that even severe mental disabilities virtually never negate mens rea. Mental disabilities may give someone a crazy motive for forming an intent, or may to some extent compromise a person’s ability to control himself. However, mental disabilities do not prevent the formation of the mens rea except in exceptionally rare cases, such as Wetmore [People v. Wetmore, 22 Cal. 3d 318, 583 P.2d 1308, 149 Cal. Rptr. 265 (1978)], where the alleged burglar’s delusional belief that he was in his own apartment negated the felonious intent (to steal) that is part of the mens rea of burglary.
Stephen J. Morse & Edward (Ned) Cohen, Diminishing Diminished Capacity in California, 2 Cal. Law. 24, 25 (June 1982).
Dr. Whitehill apparently attempted to clarify this point later in his testimony:
In my experience with Mr. Ellis, and in my experience of persons like him who have committed severely violent acts, and who manifest severe personality disorders, that which have individuals who become, or who display what we could call borderline rage—borderline not in the sense that it’s almost rage, this is clearly extremely rageful behavior. Borderline rage is not—this is rage that accompanies the borderline personality. And there are—my diagnosis of Mr. Ellis was not that of borderline rage. It was borderline personality NOS, or not otherwise specified, which there are a variety of elements present, including the borderline and antisocial behavior.
Report of Proceedings at 48 (June 16, 1997).
Dr. Whitehill wrote: “In particular, I have argued that Mr. Ellis’s mixed personality disorder and intermittent explosive disorder were in acute symptomatic presentation at the time of the slayings of his mother and half-sister.” Clerk’s Papers at 52. He “presumes” these symptoms were present, resulting in “severe impairment” on the night of the murders because the murders occurred. Id. If Ellis had not been in “acute symptomatic presentation” he presumably would not have committed the murders.
“[T]here is no scientific basis for measuring a person’s capacity for self-control or for calibrating the impairment of that capacity. There is, in short, no objective basis for distinguishing between offenders who were undeterrable and *547those who were merely undeterred, between the impulse that was irresistible and the impulse not resisted, or between substantial impairment of capacity and some lesser impairment.” Richard J. Bonnie, The Moral Basis of the Insanity Defense, 69 A.B.A. J. 194, 196 (1983).
One wonders if Ellis’s mental disorders would have prevented him from premeditating coolly to kill his mother and sister, or whether his mental disorders prevented him from premeditating only when he was “rageful.”