The History and Theory of Vitalism. By Hans Driesch. (Macmillan
and Co. 5e. net.)—Mr. C. K. Ogden's excellent translation of Professor Drieech's well-known book has bad the advantage of a thorough revision by the author, who has also rewritten the whole of the systematic section for this English edition. The doctrine of Vitalism, with which Professor Driesch's name is so prominently associated, is clearly set forth in these pages, both in its historical and theoretical aspects. Ever since Aristotle it has been a matter for discussion with biologists whether the purposive element in vital processes is merely the outcome of chemical and physical factors, or whether it is the result of some new factor peculiar to life itself. Professor Driesch takes the latter view, holding that life is "not a mere field of chance," and cannot be explained by any purely mechanical theory.