First, Professor Ferri gives the classic formula of historic materialism, set forth by Marx in his “Zur Kritik der politischen Oekonomie”, taken by the author, however, from Loria’s criticism of the work of Puviani in the “Rivista critica delle scienze giuridiche e sociali.” “In the memorable preface to the Kritik der politischen Oekonomie, published in 1859, Marx sets forth for the first time the daring theory that all the manifestations of mankind, in the juridic order as well as in the religious, philosophical, artistic, criminal, etc., are exclusively determined by economic relations, so that to each phase of these there corresponds a different form of human manifestations, as its necessary product.” Just as in biology the phenomena of nutrition are related to the other vital phenomena, so is the economic aspect of human activity related to the other aspects. Economic conditions have, then, a great influence on the social life, but the author believes it an exaggeration to say that economic conditions fix it exclusively. Further, in this statement no attention is paid to the fact that the other phenomena react in their turn upon the economic conditions, and therefore become determining factors. Then it is said that man will be morally better when he finds himself in a purified atmosphere. This the author admits in part—how far he admits it will be easily understood by one who knows his opinion with regard to the physical, individual, and social factors of crime, and his ideas about education.