but he borrows the results of special investigations in biology, physiology, history, psychology, statistics, and administration, and he shows how sociology, without discovery of any new materials, is able to combine the elements of special discoveries and to make them socially useful. This composition is as truly an original scientific work as the elementary studies. Sociology is treated as taking physiology and psychology for granted, as biology takes chemistry as a finished product. At the same time he illustrates the necessity of direct discipline in the previous sciences, since their method of research cannot be used by one who has not had practice in them. Of course, the recommendations from economic, political, technical, legislative and educational spheres are not made authoritative by the sociologist. Their acceptance will be determined by the verdicts of the masters in the several departments. But the combination of factors is as distinctly a new thing as the dramas of Shakespeare were new, although the words and stories were already in existence as unrelated facts before he was born. The importance of sociology as a study for all thoughtful citizens is shown by the fact that the preventive measures recommended require the intelligent cooperation, not only of statesmen, but of teachers, parents, physicians, pastors, editors and all who mould opinion or direct affairs.
The third chapter on practical reforms challenges more severe criticism and invites more conservative deliberation. When a scientific man passes from the explanation of facts through causes to the prevision of consequences and the recommendation of novel measures he touches subjects of the greatest interest and the greatest difficulty. Yet if the rationale did not assist in the purposive action it would have, indeed, a great attraction for the intellect, but would not promote amelioration. Of course, all truth eventually influences conduct and yields satisfactions beyond those of gratified curiosity. Professor Ferri passes to this contested ground where observation must be supplemented by experiment. He does not make this quite clear. All modifications of legislation, administration or custom are actually social experimentation. Perhaps this consideration might tone down the somewhat dogmatic confidence with which the new methods are introduced. These methods of the "positive" school relate to procedure and to penal treatment.
The positive innovations proposed in respect to judicial procedure are all related to these two general principles: (1) "the equal recog-
