I. This teaching of psychological and ethical science is to-day the received rule of action followed by the courts of justice in England and the United States. Sound philosophy and positive law are in perfect agreement on this subject. But it was not so a hundred years ago. It is wonderful to us now how strange and erroneous were the views of insanity formerly entertained by English jurists. For instance, when, in 1723, Arnold was tried for shooting at Lord Onslow, the instruction given to the court was that, for one to be exempt from punishment in such a case, "it must be a man that is totally deprived of his understanding and does not know what he is doing, no more than an infant, than a brute or a wild beast." On such a theory, very few lunatics indeed would be acquitted; few ever are so totally demented. The first jurist that pointed out the true test of insanity was Lord Erskine, who, in 1800, when Hudfield was tried for shooting at the king, delivered a celebrated speech, in which he maintained that the real test of insanity was in delusion: if delusion existed the man was insane; else, he was not insane. The deluded man, he said, might reason with admirable logic from his false principles; he was nevertheless demented if he mistook his imaginations for realities, and did so irresistibly and persistently. Erskine's test has been, from that time on, followed in the courts of England. But you will notice, on careful consideration, gentlemen, that while the principle is correct so far as it goes, it does not go far enough to cover all cases of disputed responsibility. It will apply, indeed, to all cases of total insanity, that is, when the delusion existing in a lunatic's mind affects a variety of subjects; then his premises are never reliable, and therefore he cannot be held accountable for any of his acts. But what if his insanity is partial only, if he is a monomaniac, deranged on one point and sound in mind on all other matters? This was not clearly understood till about the middle of the present century. In order to secure uniform views and action on this important matter, the British Parliament, in 1843, proposed various questions to the judges, with a request that they would agree upon and report answers. This investigation, and in fact the whole history of English legislation on insanity, is briefly and yet clearly explained in an article of Rev. Walter Hill, S.J., which appeared in the "American Catholic Quarterly Review" for January, 1880. The first question was: What was the law respecting the crime of one who is partially deluded but not insane in other respects, when he commits what he knows to be a crime in order to redress some wrong or obtain some public benefit? The answer was that such a one, even though insane, is to be punished for the crime which he knew he was committing.