We must now turn to the question of cause. If we can account for Jean Gianini's imbecility, it will be much easier to believe in it. Much has been written on the subject of the causes of feeble-mindedness. Certain fundamental principles have been agreed upon. It is now known that at least 66 per cent of feeble-mindedness is hereditary; that is to say, the individual is feeble-minded because he comes from stock in which feeble-mindedness exists. There is another group in which there are practically no other feeble-minded persons in the family or among the ancestors so far as can be discovered, but there is, on the other hand, a great deal of bad physical history; there may be epilepsy, alcoholism, insanity, or other serious physical disturbances. Finally, we have a group in which there is history of some accident, either to the child at the time of birth or after birth, or to the mother previous to the birth of the child. In Jean's case we have no history of accident or injury to the child himself. The pedigree or family tree has not been worked up and we do not know what there may be. It was in evidence that the grandfather was born on the south side of the Alps; and there was some slight attempt to imply, since cretinism is very common in that region, that possibly there was some cretinous condition in the family. All this is not impossible; and if it existed in the grandfather or even in the great-grandfather, such a condition might reappear in the grandson in the form of imbecility; yet in view of our present knowledge, or rather our lack of knowledge on this subject, this line of argument is too vague to enable us to draw any conclusions. The fact that the mother of Jean was insane and alcoholic justly had great weight. Before her first child was born she broke down mentally and was probably never "right" after that time. The first child lived to the age of seven and from the description was clearly an idiot. The second child is entirely normal. Jean, who is the third child, did not talk until he was five years old. Our general studies have not yet gone far enough, and certainly our study of this particular family is far from sufficient, to enable us to decide whether this is a matter of heredity or whether we shall say that Jean's condition as well as that of the first child is traceable directly to the mother's insanity or to her alcoholism. For the present purpose, of course, it does not matter. We see in these facts, whether we regard them as causes or merely as symptoms of a deeper lying cause, sufficient reason for Jean's being an imbecile. There is every reason to believe that Jean Gianini is an imbecile of high grade. The next important question that arises is a legal one of whether, being an imbecile of high grade, he knew the nature and quality of his act and that it was wrong.