delivered the opinion of the court, January 4th 1875.
The chief question in this case arises under the fifth point of the prisoner, which was negatived by the court below. It is this:—
5. If the jury have a reasonable doubt of the sanity of the prisoner at the time of the killing, they cannot convict.
The industry of the able counsel of the prisoner has collected and classified many cases on this point. While we think their weight accords with our own conclusions, we cannot help perceiving, in their number and variety, that the decision of the question should rest rather on a sound basis of principle than' on the conclusions of other courts. In order to apprehend the true force of the principles to be applied, we must keep in the foreground the facts of the case before any question of insanity can arise. Insanity is a defence. It presupposes the proof of the facts which constitute a legal crime, and is set up in avoidance of punishment. Keeping in mind, then, that an act of wilful and malicious killing has been proved and requires a verdict of murder, the prisoner, as a defence, avers that he was of unsound mind at the time of the killing, and incapable of controlling his will; and therefore that he is not legally responsible for his act. This is the precise view that the statute itself takes of the defence, in declaring the duty of the jury in respect to it. The 66th section of the Criminal Code of 31st of March 1860, taken from the Act of 1836, provides : “ In every case in which it shall be given in evidence upon the trial of any person charged with any crime or misdemeanor, that such person was insane at the time of the commission of such offence, and he shall be acquitted, the jury shall be required to find specially whether such person was insane at the time of the commission of such offence, and declare whether he was acquitted by them on the ground of such insanity.” Thus the verdict must find the fact of insanity, and that the acquittal is because the fact is so found. The law then provides for the proper custody of the insane prisoner. This being the provision of the statute, it is evident that a jury, before finding the fact of insanity specially, must be satisfied of it by the evidence. A reasonable doubt of the fact of insanity cannot, therefore, be a true basis of the finding of it as a fact and as a ground of acquittal and of legal custody. To doubt one’s sanity is not necessarily to be convinced of his insanity. It has been said in a nearly analogous case, “ As to whether a reasonable doubt shall establish the existence of a plea of self-defence, I take the law to be this: If there be a reasonable doubt that any offence has been committed by the prisoner, it operates to acquit. But if the evidence clearly establishes, the killing by the prisoner, purposely, with a deadly weapon, an illegal homicide of some kind is established, and the burden then falls upon the prisoner, and not on the Commonwealth, to show that it was excusable as an act *424of self-defence. If, then, his extenuation is in doubt, he cannot be acquitted of all crime, but must be convicted of homicide in some one of its grades — manslaughter at least Commonwealth v. Drum, 8 P. F. Smith 22. Such also was the opinion of the late Chief Justice Lewis, a most excellent criminal law judge, when president of the Lancaster county Oyer and Terminer, in the trial of John Haggerty, in the year 1847 : Lewis’s U. S. Criminal Law, p. 402. He said, p. 406 : “ Thet jury will decide upon the degree of intoxication, if any existed, and upon the existence of insanity. The burden of proof of this defence rests upon the prisoner; the fact of killing under .circumstances of deliberation detailed.in this case being established, the insanity which furnishes a defence must be shown to have existed at the time the act was committed. The evidence must be such as satisfies the minds of the jury.” Thus, according to both statutory and judicial interpretation, the evidence to establish insanity as a defence, must be satisfactory, and not merely doubtful.
If we now analyze the subject, we shall find that this is the only safe conclusion for society, while it is just to the prisoner, Soundness of mind is the natural and normal condition of men, and is necessarily presumed, not only because the fact is generally so, but because a contrary presumption would be fatal to the interests of society'. No one can justly claim irresponsibility for his act contrary to the known nature of the race of which he is one. He must be treated and be adjudged to be a reasonable being until a fact so abnormal as a want of reason positively appears. It is, therefore, not unjust to him that he 'should be so conclusively presumed to be until the contrary is made to appear on his behalf. To be made so to appear to the tribunal determining the fact, the evidence of it must be satisfactory and not merely doubtful, as nothing less than satisfaction can determine a reasonable mind to believe a.fact contrary to the course of nature. It cannot,'therefore, be said to be cruel to the prisoner to hold him to the same responsibility for his act, as that to which all reasonable beings of his race are held, until the fact is positively proved that he is not reasonable. This statement derives additional force from the opinion of Chief Justice Gibson in the case of The Commonwealth v. Mashler, tried before him and Justices Bell and Coulter, in Philadelphia, and quoted from in Lewis’s U. S. C. L. 403-4. “ Insanity,” he says, “is mental or moral, the latter being sometimes called homicidal mania, and properly so. A man may be mad on all subjects, and then, though he may have a glimmering of reason, he is not a responsible agent. This is general insanity ; but if it be not so great in its extent or degree as to blind him to the nature and consequences of his moral duty, it is no defence to an accusation of crime. It must be so great as entirely to destroy his perception of right and wrong, and it is not until that perception is *425thus destroyed that he ceases to be responsible. It must amount to delusion or hallucination controlling his will, making the commission of the act, in his apprehension, a duty of overruling necessity.” Again: “Partial insanity is confined to a particular subject, being sane on every other. In that species of madness it is plain that he is a responsible agent if he were not instigated by his madness to perpetrate the act. He continues to be a legitimate subject of punishment, although he may be laboring under a moral obliquity of perception, as much so as if he were merely laboring under an obliquity of vision.” And again: “The law is that whether the insanity be general or partial, the degree of it must be so great as to have controlled the will of its subject.and to have taken from him the freedom of moral action.” Thus all the utterances of the Chief Justice on this subject are positive and emphatic, and allow no room for doubts, or merely negative expressions.
And if this reasoning were even less than conclusive, the safety of society would turn the scale. Merely doubtful evidence of insanity would fill the land with acquitted criminals. The moment a great crime would he committed, in the same instant, indeed often before, would preparation begin to lay ground to doubt the sanity of the perpetrator. The more enormous and horrible the crime, the less credible, by reason of its enormity, would be the evidence in support of it; and proportionately weak would be the required proof of insanity to acquit of it. Even now the humanity of the criminal law opens many doors of escape to the criminal. Then a wider door would be opened by the doubtful proof of insanity made still more open by the timidity of jurors, their loose opinions on the' subject of punishment, and their common error that the punishment is the consequence of their finding of the truth of the facts, instead of the consequence of the commission of the crime itself. The danger to society from acquittals on the ground of a doubtful insanity demands a strict rule. It requires that the minds of the triers should be satisfied of the fact of insanity. Finally, we think this point has been actually ruled by this court in the case of Lynch v. Commonwealth, decided at Pittsburg, in 1873. The prisoner’s second point was in these words: “ That if the jury hid a reasonable doubt as to the condition of the defendant’s mind at the time the act was done, he is entitled to the benefit of such doubt, and they cannot convict.” The court below said in- answer: “ The law of the state is that where the killing is admitted, and insanity or want of legal responsibility is alleged as an excuse, it is the duty of the defendant to satisfy the jury that insanity actually existed at the time of the act, and a doubt as to such insanity will not justify a jury in acquitting upon that ground.” This ruling was sustained. Opinion by Read, C. J. See Pitts-burg Legal Journal 14, 53.
*426The assignments of error to the overruling of the prisoner’s challenge of jurors for cause are not sustained. We think the court below followed the rulings in Staup v. Commonwealth, 24 P. F. Smith 458, and O’Mara and Irwin v. Commonwealth, 25 P. F. Smith 424. It is argued that this case is distinguishable on the ground that some of these jurors had formed their opinions in part on the testimony taken before the coroner, as read in the newspapers. But it must be noticed that these jurors did not entertain very positive or decided opinions, and they stated that they were the results of rumor and newspaper statements in part. All were clear that their opinions were so unfixed, they could hear and determine the case on the evidence given in the trial below, uninfluenced by their previous impressions. They did not appear to have prejudged the case, or to have fixed and decided opinions. That evidence would be required to change their first impressions, has but little weight. Such must always be the fact, even in the case of slight impressions or loose opinions. An impression once formed, necessarily exists until something else changes it. The inquiry, therefore, turns upon the character of the opinion. Is it a prejudgment of the case? Has it such fixedness and strength as will probably influence and control the juror’s verdict — or has it been formed upon the same evidence substantially as will be given upon the trial? Much weight, therefore, is to be given to the judgment of the court below, in whose presence the juror appears and by whom his manner and conduct, as well as his language, are scrutinized. In relation to the evidence given before the coroner, we may also remark that we do not regard it as having the same weight as the testimony given at the trial of the cause. We know the looseness with which these investigations are generally conducted, especially since the law permitting them to be had before justices of the peace, in lieu of the coroner. We are not now speaking of their legal effect, but of their weight in point of fact, as a basis of a public opinion in which a juror probably participates. In determining its weight in the case of a particular juror, regard will be had in the examination to the real nature and character of the testimony taken before the inquest. In the case of Alexander McClure, a juror, it is said his opinions were denominated by himself as “ conclusions,” and therefore stood upon a higher ground of exception than mere floating opinions. But a careful examination of his statement convinces us by the wrord “ conclusion,” he did not intend to convey the meaning of con elusiveness. It was only a loose use of the word in the sense of opinion, having no fixedness or conclusiveness in his mind.
In none of the assignments of error do we discover a sufficient ground of reversal of the judgment. The sentence of the Court of Oyer and Terminer is, therefore, affirmed, and it is ordered that the record of the case be remitted to the said court for execution of the sentence.