Being thoroughly convinced of the existence of criminal natures, and being, as a utilitarian, hostile to all metaphysics, it was inevitable, when he came to consider the fundamental aim of the institutions of law and the State, that he should be led to reject all methods of treating criminal natures which did not involve their complete removal or lifelong exclusion from the life of free society. Thus, a large proportion of his subsequent life was spent in endless controversies directly against the traditional legal systems and institutions which did not harmonize with the position he had taken up. He did not seek these controversies, but he could not and would not attempt to avoid them. Throughout them, however, he remained the anthropologist, the collector and investigator in the wide field of the natural history of mankind, one more interested in studying the origin of the socially significant varieties of mankind, of which civilized man is one, than in the description of the differential characters of the races of mankind now living in various parts of the world—although investigations in this latter field were by no means repugnant to him. Lombroso’s great synthetic studies of the natural history of the criminal came to an end in the year 1902, with the publication of the German edition of his book upon the Causes and Prevention of Crime. Some months later appeared a work by Aschaffenburg on Crime and its Prevention. Even after 1902 Lombroso continued to write upon this subject, more especially in his periodical devoted to criminal anthropology; and down to the last year of his life he followed closely the progress of international research in this field. But it seems to me that the book of 1902, published at the close of thirty years’ work, marks the end of his inner development, whilst the Congress for Criminal Anthropology held in the year 1906, in which he was able to hold a review of his disciples, co-workers, friends and rivals, gave a fitting outward conclusion to his career, when he had already passed his seventieth year. During the last years, and, above all, during the last months of Lombroso’s life, a tendency to pessimism became clearly manifest; and this tendency was, owing to his peculiar organization, closely connected with a strong bent towards mystic contemplation. But this, in my opinion, has no bearing whatever upon his crimino-anthropological researches. His doctrine of the “born criminal” was in no way based upon a pessimistic foundation. In the field of social reform, including criminology, he was definitely optimistic. The weak, the sick, and the degenerate, were regarded by him at once with the objectivity and the philanthropy of the born physician. It was only in his moral valuation of the genius, and of the great condottieri and conquistadores of modern industrial life, that he lacked mildness; indeed, in this latter respect he rather inclined to severity.