NEW BOOKS. 135 c. vii. of the first edition is divided into two ; and two new chapters have been added (pp. 551-616), "Das Princip der formalen Zweckmassigkeit " (c. xv.) and "Das System des kritischen Idealismus" (c. xvi,). For the rest, while the general plan of the work is preserved, the modifications do not consist merely in additions ; those parts that are substantially identical with the chapters of the first edition have been thoroughly revised, in many cases rearranged and rewritten. That which has been from the first the author's view of Kant is thus restated : " Till the time of Kant there was metaphysic as art ; only with him begins metaphysic as science " (p. 576). The historical is not to be disconnected from the " systematic " view of Kant ; in the importance, other than historical, of Kant's work for every student of philosophy is the real justification of that minute study of his words that has been called "Kant-philology". The principal new deve- lopments in this edition are in two directions. In order to make more complete the exposition of that part of the theory of experience that has the closest connexion with the ethical theory, the doctrine of Ideas had to be " taken up into the doctrine of Experience ". This has been done on the basis of the author's intermediate work, Kant's Begrundung der Ethik (see MIND, Vol. iii. 153) the ethical doctrine itself being of course excluded from the present exposition. For this rehabilitation of the part of the doc- trine of Ideas that belongs to the theory of Experience, " the quintessence of the Synthetic Principles," the account of which the author considers to have been defective in the first edition, had to be sufficiently developed. Adequate treatment of the whole body of them became easier when the principle of Intensive Quantity was disclosed as central among them ; while also their elements Space, Time, and the Categories had new light thereby thrown upon them. Insight into the significance of the central principle, joined with consideration of the principle of Anticipations, determined the second direction in which new developments have been found necessary. It was seen that Kant's relations to mathematical and physical science, and in particular to Newton and Leibniz and their conception of infinitesimals, required more exact definition. The author's work, Das Princip der Infinitesimal-Mtthode und seine Geschichte (see MIND, Vol. ix. 159) was intended to supply the basis, so far as this conception is concerned, for the historical view now sketched in the Introduction. The new edition is dedicated " to the memory of Friedrich Albert Lange ". Die Lehre vom apriorischen Wissen in Hirer Bcdeutung fur die Entwicklung der Ethik und Erkenntnisstheorie in drr Sokratisch-Platonischcn Philo- sophic. Von Dr. phil. M. GUGGENHEIM. Berlin : Diimmler, 1885. Pp. 79. The development of Plato's doctrine of a priori knowledge is here treated in relation to his ethics. In the putting of the Socratic question as to the nature of virtue in the Meno, the author sees the starting point of this whole development, which in the Phcedo culminates in the distinc- tion between the worlds of " being," " the true," " the good," on the one hand, and of "becoming," " the false," "the bad," on the other ; the former of these being the object of e7rurrf]p.T], the latter of ^ev8f]s 86^a. In the middle of the development comes the TheasMus, where the most important distinctions of the Platonic theory of knowledge are to be traced ; and here, accordingly, is for the author the centre of interest. In his last two sections (pp. 37-79) he discusses minutely the polemic against Protagoras ; showing how a positive doctrine of a priori knowledge was developed in opposition to Sensualism by means of this polemic, and how it was con- nected in the mind of Plato with " the ethical-aesthetic ideas " which were the beginning and the end of his philosophy.
