From the year 1724 there is a dictum of an English judge to the effect that a man who is to be exempted from punishment "must be a man that is totally deprived of his understanding and memory, and doth not know what he is doing, no more than an infant, than a brute, or a wild beast."[177] From the beginning of the nineteenth century, the power of distinguishing right from wrong in the abstract was regarded as the test of responsibility;[178] whilst in the existing doctrine, dating from the trial of M[(]Naughten in 1843, the question of knowledge of right and wrong, instead of being put generally and indefinitely, is put in reference to the particular act at the particular time of committing it.[179] This series of doctrines certainly shows a noteworthy progress {276} in discrimination. But at the same time the answers given by the fourteen English judges to the questions put to them by the House of Lords in consequence of M[(]Naughten's case still display an ignorance which would nowadays be hardly possible. In reply to the question--"If a person under an insane delusion as to existing facts, commits an offence in consequence thereof, is he thereby excused?"--the judges declared that, on the assumption "that he labours under such partial delusion only, and is not in other respects insane, . . . he must be considered in the same situation as to responsibility as if the facts with respect to which the delusion exists were real. For example, if under the influence of his delusion he supposes another man to be in the act of attempting to take away his life, and he kills that man, as he supposes, in self-defence, he would be exempt from punishment. If his delusion was that the deceased had inflicted a serious injury to his character and fortune, and he killed him in revenge for such supposed injury, he would be liable to punishment."[180] The mistake committed in this answer does not lie in the conclusion, but in the premise. "Here," as Professor Maudsley observes, "is an unhesitating assumption that a man, having an insane delusion, has the power to think and act in regard to it reasonably; that, at the time of the offence, he ought to have and to exercise the knowledge and self-control which a sane man would have and exercise, were the facts with respect to which the delusion exists real; that he is, in fact, bound to be reasonable in his unreason, sane in his insanity."[181] Modern science, however, teaches us another lesson. It has shown that a delusion of the kind suggested never stands alone, but is in all cases the result of a disease of the brain which interferes more or less with every function of the mind, and that few insane persons who do violence can be truly said to have a full knowledge of the nature and quality of their acts at the time they are performing {277} them.[182] A perhaps still greater defect in the doctrine of the fourteen judges is the absence of all reference to the