Opinion by
Mb. Justice Chidsey,The pivotal and important question presented by this appeal is whether The Mental Health Act of 1951 changed the common law test for staying criminal proceedings after verdict but prior to sentence or execution. Inasmuch as appellant’s motion for a new trial has not been argued and sentence has not been pronounced we are not concerned with possible trial errors or the merits of appellant’s conviction.
On January 13, 1954 the appellant, Norman W. Moon, appearing before the Court of Quarter Sessions of Warren County on a charge of failure to comply with a support order, shot and fatally wounded the Honorable Allison D. Wade, President Judge of the 37th Judicial District. After apprehension, appellant was indicted, tried and on May 25, 1954 convicted of murder in the first degree. The jury, rejecting appellant’s sole defense of insanity, fixed the penalty at death. About two months thereafter, on July 31, 1954, while appellant was confined in the Warren County Jail pending disposition of his motion for new trial, the county sheriff, in his capacity as keeper of the jail, petitioned the court for the appointment of a sanity commission under Section 344 of The Mental Health Act of June 12, 1951, P. L. 533, as amended, 50 PS §1224. This section of the Act provides, inter alia, that a petition for the commitment of any person detained in any penal or correctional institution who is thought to be mentally ill or in such condition that he requires care in a mental hospital, or who is thought to be a mental defective (except mental defectives convicted of first degree murder) may be made by counsel for the prisoner or the superintendent of the institution where defendant is detained or by any responsible person.
*21Without holding a hearing on the petition, the court by an order dated July 31, 1954, appointed a commission composed of two physicians and an attorney to investigate appellant’s mental condition. After examining the defendant and holding hearings at which testimony and statements were taken, the commission on October 13, 1954 filed its report with the court in which it found the following ultimate facts: “a. Norman W. Moon is in fact mentally ill. b. Norman W. Moon’s mental illness is that of dementia praecox of the paranoid type. c. This illness is chronic and continuing. d. Norman W. Moon is a proper subject for commitment to a mental hospital.”.
The findings also contained answers to three specific questions submitted by the court on October 8, 1954, namely,
“(1) Regardless of what Moon’s ideas or his feelings may be as to his own acts or behavior and although he may have a mental abnormality or illness, has he sufficient intelligence or mental ability to comprehend that by generally accepted standards an unjustifiable and inexcusable killing is considered to be wrong and a crime?
“Answer. Yes, except during the two periods of acute mental disturbance that he has exhibited.
“(2) Regardless of what Moon’s ideas or his feelings may be as to his own acts or behavior and although he may have a mental abnormality or illness, has he sufficient intelligence or mental ability to comprehend that he has been tried by a jury which found him legally responsible for such a killing and guilty of murder in the first degree, and the jury also set death as the penalty which it felt was the proper one in his case?
“Answer. Yes, except during the two periods of acute mental disturbance that he has exhibited.
*22“(3) Regardless of what Moon’s ideas or his feelings may be as to his own acts or behavior and although he may have a mental abnormality or illness, has. he sufficient intelligence or mental ability to comprehend that if the penalty set by the jury is carried out and he is sent to the electric chair, it will be in punishment for the crime of which the jury found him guilty?
“Answer. Yes, except during the two periods of acute mental disturbance that he has exhibited.”1
After reviewing the evidence taken before the sanity commission and its report and, as well, the evidence adduced at the trial, the court below on October 21, 1954 filed an opinion and order finding appellant legally sane and ordering the proceedings to continue. Exceptions filed to this order by appellant were subsequently dismissed by an opinion and order dated February 9,1955. This appeal followed. As The Mental Health Act of 1951 neither provides for nor prohibits an appeal to this Court where commitment is denied, review by certiorari may be had in the broadest sense and we may examine the record to determine whether the court’s finding amounted to an error of law or an abuse of discretion as appellant contends: Commonwealth v. Patskin, 375 Pa. 368, 375, 100 A. 2d 472.
Prior to any legislation on the subject, Pennsylvania and the vast majority of other jurisdictions consistently followed and applied the common law principle that no insane person could be tried, sentenced or executed: Commonwealth ex rel. Smith v. Ashe, *23Warden et al., 364 Pa. 93, 116, 71 A. 2d 107; Commonwealth v. Patskin, supra, p. 377. The common law concept of insanity to be applied, by a jury in determining guilt where insanity is set up as a defense against conviction was the so-called “right or wrong” test laid down in M’Naghten’s Case, 8 Eng. Rep. 718, 10 Cl. & Fin. 200, and subséquently adopted as the law of Pennsylvania in Commonwealth v. Charles Mosler, 4 Pa. 264. While the M’Naghten rule has been criticized, it remains the law of Pennsylvania when insanity is pleaded at trial: See Commonwealth v. Carluccetti, 369 Pa. 190, 200 (1952), 85 A. 2d 391. However, the test at common law and employed by the courts in determining the mental capacity of a defendant to stand trial or to be sentenced or executed is not the M’Naghten “right or wrong” test but whether the defendant is able to comprehend his position and make a rational defense. In Commonwealth v. Scovern, 292 Pa. 26, 140 A. 611, at p. 29 it was stated: “A person who, by reason of his insanity, is unable to comprehend his position and to make a rational defense cannot be tried on a criminal charge while in that condition . . .”. In Commonwealth v. Ragone, 317 Pa. 113, 176 A. 454, this Court said, quoting from Blackstone’s Commentaries, “(. . . If, after he [the defendant] • be tried and found guilty, he loses his senses before judgment, judgment shall not.be pronounced; and if after judgment he becomes of nonsane memory, execution shall be stayed; for peradventure, says the humanity of the English law, had the prisoner been of sound memory, he might have alleged something in stay of judgment or execution.’ ”. As stated by Professor Weihofen in his book “Mental Disorder as a Criminal Defense” (1954) at p. 459: “After a verdict. of guilty and before sentence is pronounced, if a defendant is found to be incapable of comprehending the nature and purpose of the proceed*24ings or of stating any reasons that may exist why sentence should not be pronounced, sentence should be stayed and the defendant, committed as an insane person until he recovers.”.
It is apparent from the three questions which the court submitted to the commission and the opinions accompanying its orders that it was of opinion that the common law test for determining mental capacity at this stage of the proceedings had not been altered by the Act of 1951. If this conclusion were sound, we would not hesitate in subscribing fully to the court’s findings and order. The commission found as a fact that appellant “. . . knew why he was in jail . . ., knew that he faced a sentence in accordance with the jury verdict . . ., knows that he is on trial for his life . . ., recalls his trial . . ., admits that no one is justified in taking anyone else’s life . . ., knows that it is not right to shoot anybody . . ., and what the consequences of his acts might be . . .”. The commission examined the appellant at some length as to his ability to cooperate with his attorneys, but made no specific finding in this regard. Appellant’s attorneys made statements before the commission that appellant was unable to adequately cooperate with them, but the court, stating that “The defendant’s own words and thoughts, as expressed by him in his own testimony before the Sanity Commission refute these opinions.”, found that “. . . the defendant, understands the nature of the proceedings against him, comprehends his position in relation thereto, and is able to cooperate with his attorneys, . . .”. We have read all of defendant’s testimony, not only before the sanity commission but at his trial, and are satisfied that, under the law as it existed prior to any legislation on the subject, the court below committed no error of law nor any abuse of discretion. However, the question presents itself whether the com*25mon law test has been superseded in Pennsylvania by statutory enactment.
The history of legislation dealing with the custody of persons charged with and acquitted or convicted of crime who become mentally ill begins with the Act of May 14, 1874, P. L. 160, but for purposes of this case we are particularly concerned with the present Mental Health Act of 1951 and its predecessor, the Act of July 11,1923, P. L. 998. Section 308 of the Act of 1923 provided : “When any person detained in any prison, whether waiting trial or undergoing sentence . . . shall, in the opinion of the . . . warden, ... be insane, or in such condition as to make it necessary that he be cared for in a hospital for mental diseases, the said . . . warden, .. . shall immediately make application, ... to a law judge of the court having jurisdiction of the charge against said person, or under whose order he is detained, for commitment of said person to a proper hospital for mental diseases. The said judge shall forthwith order an inquiry ... by a commission . . . who shall immediately examine the said person and make written report of their findings to the said judge . . . The said judge may, in his discretion, summon other witnesses and secure further evidence. If he is then satisfied that the person thought or alleged to be insane is in fact insane, he shall order the removal of such person to a hospital for mental diseases . ..”. (Emphasis supplied). We construed the language “any person detained in any prison, whether waiting trial or undergoing sentence” as including a person sentenced to death, since a part of his sentence is that he be imprisoned until his execution: Commonwealth ex rel. Smith v. Ashe, Warden et al., supra, p. 117. To this extent the 1923 Act adopted the common law rules relative to a stay of execution for a defendant who became insane subsequent to verdict.
*26The Mental Health Act of June 12, 1951, P. L. 533, as amended, 50 PS §§1071-1622, was the first general revision and comprehensive codification of the Mental Health Laws since the Act of 1923. Under Section 343 of this Act the trial court is empowered to defer sentence and order a mental examination of any person convicted of a crime punishable by sentence to a penal or correctional institution. While this section would appear to restrict the application of the Act solely to persons convicted of crimes punishable by sentence to a penal institution, as previously indicated, Section 344 covers persons detained in any penal institution and it impliedly includes persons convicted of first degree murder who are mentally ill by expressly excluding in that classification only mental defectives: Cf. Commonwealth ex rel. Smith v. Ashe, Warden et al., supra. Section 345 of the Act provides that after receipt of the application for commitment and notice to the prisoner’s counsel and an examination of the person sought to be committed by a commission, “ (d) If the court is satisfied that the person sought to be committed is mentally ill or mentally defective, it shall order the commitment or transfer of such person to a mental hospital or an institution for mental defectives . . .”. (Emphasis supplied)
It will be readily observed that the basic dissimilarity between Section 345 of the Act of 1951 and Section 308 of the Act of 1923 is the substitution of the words “mentally ill or mentally defective” in the later enactment for the term “insane” in the earlier Act. This difference in terminology is employed with substantial uniformity throughout the 1951 Act. On the ground that this change of language in the 1951 legislation signifies a change of meaning by the Legislature in order to bring penology into closer accord with present day medical science, appellant contends that *27the court below abused its discretion and committed an error of law in applying the common law test of insanity rather than the statutory standard of mental illness. It is a canon of statutory construction that where words of a later statute differ from those of a previous one on the same subject, they presumably are intended to have a different construction: Fidelity Trust Company v. Kirk et al., 344 Pa. 455, 25 A. 2d 825; Panik v. Didra, 370 Pa. 488, 88 A. 2d 730; McFarland Estate, 377 Pa. 290, 296, 105 A. 2d 92.
The term “mental illness” is defined in Section 102(11) of the 1951 Act as “. . . an illness which so lessens the capacity of a person to use his customary self-control, judgment and discretion in the conduct of his affairs and social relations as to make it necessary or advisable for him to be under care. The term shall include ‘insanity’, ‘unsoundness of mind’, ‘lunacy’, .‘mental disease’, ‘mental disorder’ and all other types of mental cases, but the term shall not include ‘mental deficiency’, ‘epilepsy’, ‘inebriety’, or ‘senility’, unless mental illness is superimposed.”. (Emphasis supplied). Although this definition includes insanity, we disagree with the lower court’s conclusion that it comprehends only legal insanity. It also expressly embraces “ ‘mental disease’, ‘mental disorder’ and all other types of mental cases”, thereby indicating that the statute was intended to comprise mental abnormalities which would not come within the strict connotation of the term legal insanity. Where the lawmaking body has the power to enact legislation in a particular field, as it has here, and has manifested its intention, wé are not at liberty to distort the language of the enactment and by judicial legislation provide for what we might consider a more socially desirable result: Mamlin v. Genoe et al., 340 Pa. 320, 17 A. 2d 407. When Section 345 of the 1951 Act is read in conjunction with the stat*28utory definition of mental illness, we think it plain beyond cavil. that the Legislature has broadened the test to be used in staying criminal proceedings.
To what extent has the test been enlarged? At first glance the wordage of the Act would make it appear that every conceivable type of mental illness, with the exception of those specifically excluded, would fall within its scope and require commitment. Upon closer scrutiny it becomes evident that the controlling factor is the degree or extent to which the mind is affected by the mental disorder and not the bare existence of symptoms which would induce a psychiatrist to diagnose a mental illness. This conclusion is confirmed by Section 343(c) of the Act which provides that “On the report of the examiner that the defendant is so mentally ill or defective that it is advisable for his welfare or the protection of the community that he be committed to other than a penal or correctional institution, the court may commit him, ... If the examiner’s report indicates no such mental illness or deficiency, he shall be sentenced as in other cases.”. (Emphasis supplied). Here the commission found that appellant possessed well marked symptoms of psychosis which it further characterized as dementia praecox. This condition, a recognized form of mental disorder was, if justifiably diagnosed,2 within the purview of the Act, but having resolved that appellant was mentally afflicted, the determinative issue was whether that illness so lessened his capacity to use his cus*29tomary self-control, judgment and discretion as to render it necessary or advisable for him to be under care. As clearly delineated in the statutory definition, this is the standard which the Legislature promulgated to guide the commission and the court.
Assuming the commission found appellant a proper subject for commitment under this standard, its findings while persuasive were nevertheless advisory only and not mandatory upon the court, for under Section 345(d) of the Act it is the court and not the commission which must be satisfied that appellant is mentally ill under the standard prescribed. It follows that the court in the instant case could have rejected, although not arbitrarily or capriciously, the commission’s findings and conclusions and could have independently determined from the evidence that appellant’s capacity to use his customary self-control, judgment and discretion had not been so lessened that it was necessary or advisable for him to be under care. In view of the fact, however, that the court, in misapprehending the effect and intendment of the 1951 Act, did not apply this standard it thereby committed an error of law, and we have no way of ascertaining whether it would have arrived at a similar conclusion under the criterion so laid down. Accordingly the commission’s findings and recommendation must be reexamined and the evidence reconsidered by the court together with any additional relevant evidence in the light of the statutory definition of mental illness.
The order of the court below is reversed and the record is remanded for procedure consonant with this opinion.
The two periods of acute mental disturbance referred to in tbe answers to tbe three questions submitted by tbe court occurred, according to the commission’s report, “. . . tbe first time in the jail at the time of his commitment and the second time while in the hospital after the Commission first met.” and the commission found that “On both occasions his disturbance promptly subsided.”.
In its opinion dismissing the exception to its order, the court said: “. . . it seems likely to the court that the symptoms on which the members of the Sanity Commission based their opinion that Norman W. Moon was mentally ill might well be exhibited by any one convicted of murder in the first degree by a jury which set the death penalty, under the stress of his confinement and contemplation of his fate . . .”.