First. A really scientific examination of the causes of criminality is only possible since the existence of criminal statistics, i.e. since the beginning of the 19th century. [266] Second. Criminality has increased greatly under capitalism, and is of the greatest importance to the whole social life. Third. An examination of historic criminality is very interesting; that of our own day is still more so. However, social science is not simply a means of solving interesting problems, but also, and chiefly, a means of pointing out to society the way to protect itself from scourges like criminality, or if possible, to get rid of them entirely. Here the saying of Marx applies: “The philosophers have only interpreted the world differently; the important thing is to alter it.” Above I have already remarked that some authors have an opinion that differs from that of the majority, and are in agreement with the theory cited. Among these must be cited Engels, one of the two founders of this theory, and most of the authors of whom I spoke in the last chapter. However, Engels has only made, in passing, some observations upon the influence of capitalism on crime among the workers in factories; Hirsch, in his interesting brochure, has pointed out only certain sides of the economic life; and although the studies concerning this question published by Lafargue and by Lux are more complete than those of the first two authors, there are nevertheless important points which these last have not examined, or to the bottom of which they have not gone, as it seems to me. And it is quite comprehensible that it should be so; for the work of Lafargue is only a magazine article, and that of Dr. Lux is one of the subdivisions of a social-political manual, in which he treats of crime among other social phenomena. The works of the other authors noticed in Chapter VII, do not make the study of the question in the manner noted, useless. I am of the opinion, then, that while the works quoted have made considerable progress, there is still much to be done. It therefore appears to me that it will not be without profit to take up the subject. The theory of Marx and Engels results in our having a method of investigation already marked out. While most authors who have published studies upon the question, have thought it unnecessary to give an exposition of the economic system in which we live, or perhaps have given a little attention to it along with other social conditions, I shall begin by setting forth the present economic system as that upon which the other parts of the social life rest. These I shall treat in their turn, in so far as they are connected with criminality. It is obvious that this will be only a sketch, for if one wished all the details, it would be enough to refer to the special literature upon the subject. Then I shall investigate the question of how far criminality, under its different forms, is the consequence of the conditions we have found.