And this is why Germany, which has been the most fruitful field for the development of the Darwinian theories, is also the most fruitful field for the intelligent, systematic propaganda of socialist ideas.
And it is precisely for this reason that in Berlin, in the windows of the book-stores of the socialist propaganda, the works of Charles Darwin occupy the place of honor beside those of Karl Marx.
 LARFARGUE, Le Materialisme economique, in Ere nouvelle, 1893.
 Avoiding both of the mutually exclusive theses that civilization is a consequence of race or a product of the environment, I have always maintained—by my theory of the natural factors in criminality—that it is the resultant of the combined action of the race and the environment.
Among the recent works which support the thesis of the exclusive or predominant influence of race, I must mention LE BON, Les lois psychologiques de l’evolution des peuples, Paris, 1894. This work is, however, very superficial. I refer the reader for a more thorough examination of these two theses to Chap. IV of my book Omicidio nell’ anthropologia criminale, Turin, 1894.
 I use the expression “mercantile ethics,” which LETOURNEAU used in his book on the Evolution of Ethics (L’evolution de la morale), Paris, 1887. In his scientific study of the facts relating to ethics, Letourneau has distinguished four phases: animal ethics—savage ethics—barbarous ethics—mercantile (or bourgeois) ethics; these phases will be followed by a higher phase of ethics which Malon has called social ethics.
 Some persons, still imbued with political (Jacobin) artificiality, think that in order to solve the social question it will be necessary to generalize the system of metayage. They imagine, then—though they do not say so—a royal or presidential decree: “Art. 1. Let all men become metayers!”
And it does not occur to them that if metayage, which was the rule, has become a less and less frequent exception, this must be the necessary result of natural causes.
The cause of the transformation is to be found in the fact that metayage represents (is a form typical of) petty agricultural industry, and that it is unable to compete with modern agricultural industry organized on a large scale and well equipped with machinery, just as handicrafts have not been able to endure competition with modern manufacturing industry. It is true that there still are to-day some handicraft industries in a few villages, but these are rudimentary organs which merely represent an anterior phase (of production), and which no longer have any important function in the economic world. They are, like the rudimentary organs of the higher species of animals, according to the theory of Darwin, permanent witnesses of past epochs.