592 NEW BOOKS. ethical system up to the present time appears to him to be that of G. H. Schneider in Der menschliche Wille ; but he finds much to criticise here also. At the end of the volume the domain of ethics is marked off from that of aesthetics. It is found that " the aesthetic and moral moments develop in like progression, and there is only then a perfect moral state when there is a perfect aesthetic state". The first stage of development of the spirit, therefore, must be that which contains both art and morality in germ. This, as has already been seen, is religion. When all the products of religion are completely developed, it ceases to exist as a separate thing. Zur Losung des metaphysischen Problems. Kritische Untersuchungen uber die Berechtigung und den metaphysischen "Werth des Transcendental- Idealismus und der atomistischen Theorie. Von H. BENDER. Berlin : E. Mittler, 1886. Pp. viii., 176. The author's object is to revise Spinoza's doctrine of substance in the light of the Kantian criticism, and at the same time to incorporate' with it modern "atomism". He begins with a justification of the thing-in-itself as a legitimate part of the Kantian doctrine. " The true thing-in-itself," he concludes, can only be Spinoza's "substance," "the most perfect hei of the nature of which, however, as the Kantian criticism lias proved, I ' can be no positive knowledge (pp. 1-43). An examination of Kant's doctrine of the ideality of space and time (pp. 44-93) leads him to " a moderate idealism". Space and time are to be regarded as "forms of representation," but also as "forms of the representation of objectively real relations". " The atomistic doctrine " is found to be logically justified as a scientific conception, but to require completion by a (non-materialistic) metaphysics (pp. 94-142). From the metaphysical point of view, it is "the scientific bearer" of that "uniformity of law" by which the one substance, the naticr- of Spinoza, manifests itself in all the ch. of particular things. Finally, the author contends that the three " original categories" are "substantiality, causality, and reciprocal action" (pp. 143-76). Optische Hiiresien. Von ROBERT SCHELLWIEX. Halle a. S. : C. E, M. Pfeffer (R. Strieker), 1886. Pp. iv., 98. The author, whose philosophical doctrine is set forth in works noticed in MIND, Vols. ii. 134 and iv, (>02, here contends for the objective exist- ence of colour as a quality of things, and not (as it is often represented by physicists) a mere "subjective" product of the interaction of organism and ethereal vibrations. Mechanical movement, he contends, has no claim to be regarded as objective in a special sense. The sensible world is throughout a manifestation of the real world. To attempt to explain colour by inter- action of ethereal movements and of the organism (or of " conscious^ is illusory. "Light and colour are, are objectively effects and modes of exist- ence of things." As such, they must be explained on objective grounds. Experiments on polarisation and contrast lead to the conclusion that not only different colours but also 'bright ' and 'dark' form "a polar contrast ". Tli is contrast physiological optics tries to explain on subjective grounds, detaching it from its objective basis. The true explanation is that in the objective reality of things tin-. .^netic and polar process" through which light proceeds from darkness and darkness from light ; and in the transitional stages of this process colour originates, "which itself , belongs to a polar contrast, according as it is transition from light to dark (blue and violet) or .from dark to li^ht (red and yellow) or the union of these contraries in the bright mean (green) or in the dark mean (purple)" (p. 73). The consciousness of colour leads us back immediately to its real
