Opinion by
Mb. Chief Justice Bell,Defendant, while represented by three lawyers, pleaded guilty to the indictment charging him with murder. The Judge, sitting without a jury, found him guilty of murder in the first degree, and sentenced him to life imprisonment. Defendant’s motion for a new trial and in arrest of judgment were dismissed by the lower Court. From the judgment of sentence defendant took this appeal.
This was one of the most brutal, senseless murders ever committed. The details are so gruesome that we shall only outline them.
Defendant met the victim, Betty Sharkey, for the first time in a Bellefonte bar on the evening of June 8, 1963. After several hours of drinking at various bars, they decided in the early morning hours of June 9th to look for a motel room to spend the night. Failing in their attempts to secure a room, the victim suggested that the defendant drive his car to a secluded field just off a secondary road in Patton Township, Centre County, in order to have sexual intercourse. When they arrived there they both removed their clothing and in the language of the defendant, he started “loving her up.” For some unknown reason, she changed her mind about having intercourse and struck him with her pocketbook to prevent it. For some un*314known and unexplained motive or reason he punched Betty several times on her head and face with his fists, pushed her out of the car and then stabbed her with a penknife, inflicting some 90 wounds on her body. After this he dressed, then slashed her from her throat to her abdomen, drove his car over her body twice and then drove off, leaving her naked, lifeless body at this isolated spot. In a clever attempt to avoid detection, he washed and hid his bloodstained clothing and put on another suit.
When apprehended several hours later, he first denied any knowledge of the killing, but shortly thereafter acknowledged his guilt orally and in writing.
Defendant-appellant has two principal and several minor contentions; they are so interrelated that they will all be considered together.
We note at the outset that defendant did not take the witness stand; instead he relied upon the testimony of two psychiatrists and one psychologist who, in the last analysis, based their opinions to a large extent upon defendants self-serving, unsworn, uncorroborated statements to them about his prior life and his actions and reactions, some of which are fantastic. Neither defendant nor his counsel nor his witnesses contend that he was insane under the M’Naghten Rule. Instead, he contends (1) that there was no motive for his crime, and (2) that because of his mental condition, which was induced by feeling the breasts of his victim, or by the tremendous pleasure he got from hearing women scream in agony when he beat them up,* he could not form an intent to kill. In other words, *315defendant contends that because of his mental condition, his excitement, and his reactions when women were involved, it was impossible for him to form a specific intent to take a human lifeand consequently he could not be convicted of any crime higher than murder in the second degree. Defendant further contends that under a plea of guilty (a) there is a presumption of fact that the murder was only murder in the second degree and (b) that that degree must be so found by the Court unless the Commonwealth establishes, beyond a reasonable doubt, all the requisite elements of murder in the first degree, and (c) this the Commonwealth failed to do.
Neither defendant’s psychiatrists nor any of his witnesses, we repeat, testified that defendant was insane under the M’Naghten Rule. The testimony of defendant’s experts, if believed, would establish an irresistible impulse to violence in certain sexual situations. Psychiatric names or definitions vary or change almost as rapidly as “bridge conventions”; and the use of terms such as “irresistible impulse,” or “diminished responsibility”, or “inability to control oneself”, or “temporary partial insanity”, or various kinds of psycopaths, are not sufficient to change what the psychiatrists used to call and what, in legal language, has always been called, an irresistible impulse.
We note that defendant in his statement of the questions involved on this appeal, does not call or characterize his aforesaid actions and his emotional reactions by the name of “irresistible impulse”, but thus phrases it: “Under the circumstances above, where defendant asserted neither the defense of insanity under the M’Naghten Rule, nor irresistible impulse, but that his actions were motivated by a deep-seated anxiety, arising from repeated traumatic, pre-adolescent sexual experiences which, by their repetitive character, produced a conditioned reflex type of conduct, which erupt*316ed when triggered by specific stimuli, resulting in a mental state which temporarily destroyed his ability to premeditate and form specific intent, is such evidence admissible to disprove the existence of intent and premeditation?” Premeditation and a specific intent to kill are, as we shall see, essential elements of first degree (non-felony) murder.
• The defendant and the Commonwealth differ so widely about the pertinent and correct legal principles involved in this ease and the trial Judge seemed so doubtful about several applicable principles of law, as well as the effect of psychiatric testimony, that we shall briefly review and reiterate the established law in Pennsylvania. In this way we shall answer all of defendant’s contentions.
It is well established that if a defendant pleads guilty to murder, he must plead guilty to murder generally, and cannot plead guilty to either murder of the first degree or murder of the second degree. A plea of guilty to an indictment for murder constitutes an admission or confession of guilt of the crime of murder, with the degree of murder to be determined, and the penalty fixed, by the Court. The law is not clearly settled as to whether on such a plea there is a presumption or an inference of second degree murder — the distinction between a presumption of fact and an inference is often slight and shadowy. Nevertheless, all the cases agree that after a plea of guilty to murder, the burden is upon the Commonwealth to produce direct and/or circumstantial evidence which, from the facts and circumstances and all reasonable inferences therefrom is legally sufficient to prove, beyond a reasonable doubt, that the killing amounted to murder in the first degree: Commonwealth ex rel. Andrews v. Russell, 420 Pa. 4, 215 A. 2d 857; Commonwealth v. Kurus, 371 Pa. 633, 637, 92 A. 2d 196; Commonwealth v. Samuel Jones, 355 Pa. 522, 525, 50 A. 2d 317.
*317In Commonwealth v. Finnie, 415 Pa. 166, the Court epitomized the law of murder (pages 170-172) : “In Commonwealth v. Carroll, 412 Pa., supra [525, 194 A. 2d 911] the Court, quoting from Commonwealth v. Gooslin, 410 Pa., supra, pertinently said (pages 530-531) : ‘. . . “Murder”, . . . “is defined as an unlawful hilling of another with malice aforethought, express or implied.” The legislature divided murder into two classifications, murder in the first degree and murder in the second degree; and provided that (1) all murder perpetrated by poison or lying in wait; or by any other hind of wilful, deliberate [and] premeditated hilling, or any murder which shall be committed in the perpetration of or attempt to perpetrate certain specified felonies [arson, rape, robbery, burglary, or hidnapping], is murder in the first degree and (2) every other hind of murder is murder in the second degree: Act of June 24, 1939, [P. L. 872, as amended].
“ ‘ “ ‘Malice express or implied is [the hallmarh] the criterion and absolutely essential ingredient of murder. Malice in its legal sense exists not only where there is a particular ill will, but also whenever there is a wiehedness of disposition, hardness of heart, wanton conduct, cruelty, rechlessness of consequences and a mind regardless of social duty: [Commonwealth v. Kirkland, 413 Pa. 48, 195 A. 2d 338; Commonwealth v. Carroll, 412 Pa., supra; Commonwealth v. Kravitz, 400 Pa. 198, 161 A. 2d 861; Commonwealth v. Buzard, 365 Pa. 511, 76 A. 2d 394; Commonwealth v. Boden, 399 Pa. 298, 159 A. 2d 894.] Legal malice may be inferred and found from the attending circumstances. [Malice is present if the defendant had an intent (to hill or) to do the deceased serious bodily harm: Commonwealth v. Drum, supra; Commonwealth v. Dorazio, 365 Pa. 291, 74 A. 2d 125.]
“ ““ “The test of the sufficiency of the evidence— irrespective of whether it is direct or circumstantial— *318is whether accepting as true all the evidence upon which, if believed, the jury could properly have based its verdict, it is sufficient in law to prove beyond a reasonable doubt that the defendant is guilty of the crime charged, . . . [citing numerous authorities]. . . ’ ” ’
“ ‘In Commonwealth v. Kravitz, 400 Pa. 198, 161 A. 2d 861, the Court said (page 208) Proof by eye witnesses or direct evidence of the corpus delicti or of identity or of the commission by the defendant of the crime charged is not necessary. ‘It is clearly settled that a man may be convicted on circumstantial evidence alone, and a criminal intent may be inferred by the jury from facts and circumstances which are of such a nature as to prove defendant’s guilt beyond a reasonable doubt: [citing numerous authorities].’ ” ’ ”
“ ‘In Commonwealth v. Tyrrell, 405 Pa. 210, 174 A. 2d 852, the Court said (pages 212-213) : “The essential difference in a non-felony murder-killing between murder in the first degree and murder in the second degree is that murder in the first degree requires a specific intent to take the Ufe of another human being :* Commonwealth v. Ballem, 386 Pa. 20, 123 A. 2d 728; Commonwealth v. Dorazio, 365. Pa., supra; Commonwealth v. Malone, 354 Pa., supra; Commonwealth v. Chapman, 359 Pa. 164, 58 A. 2d 433; Commonwealth v. [Samuel] Jones, 355 Pa. 522, 50 A. 2d 317; Commonwealth v. Iacobino, 319 Pa. 65, 178 A. 823.”
“ ‘The specific intent to kill which is necessary to constitute in a nonfelony murder, murder in the first degree, may be found from a defendant’s words or conduct or from the attendant circumstances together with all reasonable inferences therefrom, and may be inferred from the intentional use of a deadly weapon on a vital part of the body of another human being: Commonwealth v. Tyrrell, 405 Pa., supra; Commonwealth v. Moore, 398 Pa. 198, 157 A, 2d 65; Commonwealth
* ItaUcs throughout, ours. *319v. Nelson, 398 Pa. 359, 152 A. 2d 913; Commonwealth v. Ballem, 386 Pa. 20, 123 A. 2d 728; Commonwealth v. Heller, 369 Pa. 457, 87 A. 2d 287; Commonwealth v. [Samuel] Jones, 355 Pa. 522, 50 A. 2d 317.’” Accord: Commonwealth v. Kirkland, 413 Pa., supra (pp. 63-65); Commonwealth v. Carroll, 412 Pa., supra.
In Commonwealth v. Melton, 406 Pa. 343, 378 A. 2d 728, the Court aptly said (pages 349-350) :
“There is not the remotest merit to defendant’s contention that because of Ms deficient mentality, the Court did not have the power to convict Mm of murder in the first degree.
“In Commonwealth v. Smith, 405 Pa. 456, we sustained a verdict of guilty of murder in the first degree with penalty of death, even though defendant was a sexual psychopath. We there said (pages 459-460) : “This Court lias sustained a verdict of first degree murder with penalty of death where defendant allegedly had an irresistible impulse, was a moron or a mental defective or a sexual pervert or a psychopathic personality, or had been previously confined in the hospital for the criminal insane for 14 years, or was a schisophrenic psychopath or was an unstable, mentally defective moron, or was feeble-minded: Commonwealth v. Leamer, 386 Pa. 485, 126 A. 2d 409; Commonwealth v. Cole, 384 Pa. 40, 119 A. 2d 253; Commonwealth v. Gossard, 383 Fa. 239, 117 A. 2d 902; Commonwealth v. Elliott, 371 Pa. 70, 89 A. 2d 782; Commonwealth v. Carluccetti, 369 Pa. 190, 85 A. 2d 391; Commonwealth v. Givens, 363 Pa. 141, 69 A. 2d 142; Commonwealth v. Neill, 362 Pa. 507, 67 A. 2d 376; Commonwealth v. Howell, 338 Pa. 577, 13 A. 2d 521; Commonwealth v. Hawk, 328 Pa. 417, 196 A. 5; Commonwealth v. Stabinsky, 313 Pa. 231, 169 A. 439.’ ”
Defendant in the instant case makes the same contentions as were made in the aforesaid cases, but instead of calling himself a mental defective or a sexual *320pervert, or some kind of a psycopath, or that he had an irresistible impulse, he contends that his is a case of “diminished responsibility.” By whatever name psychiatrists, or doctors or lawyers call it, an inability to control one’s self under certain circumstances is legally insufficient to justify an acquittal of murder, or a reduction of a first degree murder killing to second degree.
These cases not only support and justify the verdict and sentence in this case but indicate that any lesser verdict would be a travesty on Justice. Nevertheless we shall consider and analyze defendant’s contentions which are based upon the testimony of his two psychiatrists and a psychologist who testified that in their opinion defendant’s stirred-up mental condition prevented his forming a specific intent to kill Betty.
In Commonwealth v. Tyrrell, 405 Pa., supra, the Court sustained a verdict of first degree murder with penalty of life imprisonment and pertinently said (pages 219-221) : “As a result Dr. Coleman determined that the defendant was psychotic since teen age and that he was so emotionally upset on March 7, 1960, that ‘he would react to an impulse to pick up a loaded shotgun resting at his elbow and fire it at his wife, and that at that time he had no intent to take his wife’s life.’
“The doctrine of ‘irresistible impulse’ or in the modern psychiatric vernacular ‘inability to control one’s self’, whether used to denote legal insanity, or as a device to escape criminal responsibility for one's acts or to reduce the crime or its degree, has always been rejected in Pennsylvania. In Commonwealth v. Neill, 362 Pa. 507, 67 A. 2d 276, Mr. Chief Justice Steen said: ‘Apart from the fact that “confusional insanity” is apparently an antiquated and discarded theory and that the proposition that there could be such a thing as a momentary insanity was sharply challenged by an ex*321pert witness for the Commonwealth, it would seem quite obvious that defendant’s witness failed to differentiate between a mere temporary frenzy or emotional excitation, and insanity within the legal meaning of that term, namely inability, from disease of the mind, to understand the nature and quality of the act and to distinguish between right and wrong with respect to it: Commonwealth v. Szachewicz, 303 Pa. 410, 416, 417, 154 A. 483, 485; Commonwealth v. Lockard, 325 Pa. 56, 60, 188 A. 755, 757. . . . Certainly neither social maladjustment, nor lack of self-control, nor impulsiveness, nor psycho-neurosis, nor emotional instability, nor chronic malaria, nor all of such conditions combined, constitute insanity within the criminal-law conception of that term.’ [Emphasis in original]
“In Commonwealth v. Woodhouse, 401 Pa. 242, 164 A. 2d 98, defendant shot and killed his adopted daughter; this Court affirmed his conviction of murder in the first degree [with penalty of life imprisonment]. Three psychiatrists testified that defendant, at the time of the commission of the killing, was suffering from a paranoid psychosis, or from a delusion, or from a severe psychosis accompanied by serious delusions, or was a paranoid schizophrenic and at times did not know the difference between right and wrong and acted under an irresistible impulse and hence was insane. This Court, in a learned opinion by Mr. Justice Eagen, analyzed at length and firmly rejected, as this Court had often previously done, the theory of irresistible impulse as a defense in an indictment for murder. Once again this Court approved the M’Naghten Rule, which ‘was adopted as the law in Pennsylvania (Commonwealth v. Mosler, 4 Pa. 264 (1846)) and has become firmly established and imbedded in the body of the law of this Commonwealth ever since, [citing many cases, including the recent case of Commonwealth v. Novak, 395 Pa. 199, 150 A. 2d 102 (1959)].’”
*322In Commonwealth v. Carroll, 412 Pa. 525, supra, the Court aptly said (pages 534-536) : “Defendant’s most earnestly pressed contention is that the psychiatrist’s opinion of what defendant’s state of mind must have been and\ was at the time of the crime, clearly establishes not only the lack but also the legal impossibility of premeditation. Dr. Davis, psychiatrist of the Allegheny County Behavior Clinic, . . . gave his opinion that ‘rage’, ‘desperation’, and ‘panic’ produced ‘an impulsive automatic reflex type of homicide, ... as opposed to an intentional premeditated type of homicide. . . . Our feeling was that if this gun had fallen to the floor he wouldn’t have been able to pick it up and consummate that homicide. And I think if he had to load the gun he wouldn’t have done it. This is a matter of opinion, but this is our opinion about it.’
“There are three answers to this contention. First, as we have hereinbefore stated, neither a Judge nor a jury has to believe all or any part of the testimony of the defendant or of any witness. Secondly, the opinion of the psychiatrists was based to a large extent upon statements made to them by the defendant, which need not be believed and which are in some instances opposed by the facts themselves. Thirdly, a psychiatrists opinion of a defendant’s impulse or lack of intent or state of mind is, in this class of case, entitled to very little weight, and this is especially so when defendant’s own actions, or his testimony or confession, or the facts themselves, belie the opinion.
“The rule regarding the weight of expert testimony in this class of case is well settled. ‘. . . “[E]xpert testimony is entitled to little weight as against positive facts. Expert medical opinions are especially entitled to little or no weight when based upon insufficient or (partly) erroneous facts or a feigned state of mind or an inaccurate past history, or upon unreasonable deductions, . . .” [Commonwealth v. Gossard, *323385 Pa. 312, 123 A. 2d 258; Commonwealth v. Patskin, 375 Pa. 368, 375, 100 A. 2d 472].’ Commonwealth v. Jordon, 407 Pa. 575, 583, 181 A. 2d 310.
“In Commonwealth v. Woodhouse, 401 Pa. 242, 164 A. 2d 98, we held that the jury was free to disregard expert psychiatric testimony that defendant was insane at the time of commission of the hilling,— which would have acquitted the defendant under the M’Naghten Rule — in the face of testimony by lay witnesses who actually observed him and considered him to be sane at times when he was allegedly insane. Mr. Justice Eagen, speaking for the Court, said (pages 259-260) : It must be kept in mind that an opinion is only an opinion. It creates no fact. Because of this, opinion evidence is considered of a low grade and not entitled to much weight against positive testimony of actual facts such as statements by the defendant and observations of his actions.” ’ See to the same effect: Commonwealth v. Melton, 406 Pa., supra; Commonwealth v. Heller, 369 Pa., supra.”
It is too often forgotten that in criminal trials the opinion of a psychiatrist is based to a large extent upon self-serving unsworn statements given him by the defendant as to his prior life and prior thoughts, actions and reactions, as to which there is no proof, no opportunity of cross-examination and usually no corroboration. These factors are especially present in this instant case. Defendant’s psychiatrist, Dr. Clark, based his conclusion that defendant could not form an intent to kill, largely on the following unsworn, uncorroborated statement given him by the defendant:
“. . . He escorted about 75 or 100 women into the compound [in Korea] as near as he can recall. But only went out with about 25 or 30 and lie explains this that because even though he would take them into the compound, other men would take over after that and become their companions. These women he beat *324up, all these women with the exception of three. These three he had intercourse with, but he did not have any preliminary intimacies with them. After having relations with the first three women, the other men told him what they did, he had reference to preparatory-intimacies and so on. He had the urge to heat a woman after feeling her breasts. Mr. Ahearn stated that some women liked the heatings and that made him feel good and sometimes he had an orgasm at the time. After he started beating the first woman, he did not want to have sexual relations with any more women, because he felt he got more out of it by beating and hearing them yell and scream for help.”
This demonstrates more clearly than almost anything else could why the Courts of Pennsylvania believe that the opinion of a psychiatrist which is based in substantial part upon unsworn, uncorroborated self-serving statements of a criminal or an accused defendant — self-serving statements which are not even subject to cross-examination — who desires to escape conviction, is entitled to little weight and rarely ever forms a sound basis for the conclusion of the psychiatrist. Even defendant’s psychiatrists cannot agree upon what impelled defendant to commit this terrible crime— whether it was feeling his victims’ breasts, as they first testified, or whether it was a desire to beat them up in order to enjoy their screams for help. We hold that the psychiatric testimony offered in this case is not admissible (1) to absolve or exculpate and acquit a defendant of crime, or (2) to prove a lack of specific intent to kill, and thereby prohibit a verdict of murder of the first degree. This has always been the law of Pennsylvania. Commonwealth v. Tyrrell, 405- Pá., supra. We further hold that since the Act of December 1, 1959, P. L. 1621, 18 P.S. §4701, (popularly known as the Split Verdict Act), unless psychiatric testimony is introduced for the purpose of showing insanity under the *325M’Naghten Rule, (a) it is admissible only after guilt has been determined by a jury or Court, and (b) is relevant and admissible thereafter only for the limited purpose of aiding the jury or Court in fixing the penalty-
In Commonwealth v. Elliott, 371 Pa. 70, 89 A. 2d 782, (which was decided before the Split Verdict Act) the Court pertinently said (pages 75-76) : “Defendant contends that because a criminal or murderer is a weak, unstable, aggressive, dangerous moron who is mentally deficient the sentencing Judge or Court (1) must consider his record during his entire life and particularly reports of every psychologist and psychiatrist who has examined him, and (2) must be controlled by these reports and impose a sentence in the case of murder in the first degree not higher than life imprisonment. This contention carries the theory or doctrine of ‘diminished responsibility* to an extreme and would vest in a psychiatrist and not in the Courts the right and power to determine and fix punishment for crimes. Such a theory or philosophy would soon transfer the punishment of criminals from Courts to psychiatrists and would inevitably result in a further brealcdown of law enforcement and eventual confusion and chaos. Fortunately our cases are opposed to such an undesirable result.**
Defendant also contends that since there was no motive for the killing, he should either be excused entirely or the crime could not amount to murder in any degree. This contention has often been rejected by the Court.
In Commonwealth v. Kravitz, 400 Pa. 198, 161 A. 2d 861, the Court said (pages 216-217) : “In Commonwealth v. Novak, supra, the Court said (page 204) : ‘ “Evidence to prove motive, intent, plan or design are admissible [citing cases].”: Commonwealth v. Homeyer, 373 Pa. 150, 159, 94 A. 2d 743. However, “proof *326of motive is always relevant but never necessary.”: Commonwealth v. Malone, 354 Pa. 180, 188, 47 A. 2d 445.’ ”
Defendant is an exceptionally dangerous criminal who is a subtle but serious threat to law-abiding society. The verdict, penalty and sentence of the lower Court were undoubtedly justified and all of defendant’s contentions are devoid of merit.
Verdict and Judgment of sentence affirmed.
The psychiatrists first testified that defendant was stimulated to violence by feeling women’s breasts, but in other parts of their testimony they seemed to base their opinion of defendant’s “assaultive” stimulation from beating up women. Prom an analysis of all their testimony, it is not clear which was the motivating, Stimulating cause,