Let us now speak of this new science, which has become known in Italy by the name of the Positive School of Criminology. This science, the same as every other phenomenon of scientific evolution, cannot be shortsightedly or conceitedly attributed to the arbitrary initiative of this or that thinker, this or that scientist. We must rather regard it as a natural product, a necessary phenomenon, in the development of that sad and somber department of science which deals with the disease of crime. It is this plague of crime which forms such a gloomy and painful contrast with the splendor of present-day civilization. The 19th century has won a great victory over mortality and infectious diseases by means of the masterful progress of physiology and natural science. But while contagious diseases have gradually diminished, we see on the other hand that moral diseases are growing more numerous in our so-called civilization. While typhoid fever, smallpox, cholera and diphtheria retreated before the remedies which enlightened science applied by means of the experimental method, removing their concrete causes, we see on the other hand that insanity, suicide and crime, that painful trinity, are growing apace. And this makes it very evident that the science which is principally, if not exclusively, engaged in studying these phenomena of social disease, should feel the necessity of finding a more exact diagnosis of these moral diseases of society, in order to arrive at some effective and more humane remedy, which should more victoriously combat this somber trinity of insanity, suicide and crime.