1899] A LOYAL DARWINIAN 363 
follows :—He is willing to admit some use-inheritance or kinetogenesis, e.g. to 
explain the eye in flat-fishes and the tendrils of Ampelopsis; as panmixia 
cannot cause degeneracy and the principle of compensation of growth is an 
unproved hypothesis of a very doubtful character, disuse-inheritance seems to 
him necessary to explain many vestigial organs; environmental influence or 
physiogenesis is a true cause of variation, but these variations are not trans- 
mitted to other generations unless the same variation has been impressed over 
and over again on many successive generations ; the most reasonable hypothesis 
appears to be that the physico-chemical forces affect, in time, the germ-cells ; 
and that the changes thus produced become congenital variations, capable of 
being transmitted to future generations, and forming the material on which the 
various forms of selection and isolation may work. 
We must not lay down this interesting book without noticing one of its 
most remarkable features, namely, the expression of the author’s conviction that 
the outcome of the theory of evolution will be uniformity of religious belief. 
dA 
THE SCIENTIFIC SPIRIT. 
Studien und Skizzen aus Naturwissenschaft und Philosophie. I Ueber 
wissenschaftliches Denken und iiber populiire Wissenschaft. By Dr. 
Ap. WAGNER. 8vo, pp. 79. Berlin: Gebriider Borntraeger, 1899. 
Price 1 mark, 20 pfg. 
This is the first of a series of booklets intended to introduce the reader to 
the problems of science and philosophy, not by didatic discourse or condensed 
summary, but by a more humane, indeed almost conversational, method. As an 
expert might tell us the meaning of the differential calculus in much less than 
half an hour, or of the theory of organic selection in five minutes, so will the 
author of these “Studien und Skizzen” instruct us concerning evolution and 
development, the freedom of the will and egoism, instinct and morals in a series 
of dainty little books which can be carried in the breast-pocket. It is a most 
laudable intention, and the prospect held out to us becomes the more enticing 
when we are told that the reader will be brought into touch with thought rather 
than with knowledge—in short with the scientific spirit rather than with the 
body of science. 
The present volume deals with scientific thought— ‘ wissenschaftliches 
Denken ”—its aims and methods. It is easy to say—‘ the advancement of 
knowledge and the search after truth,” but the conception of knowledge and 
truth seem to be as plastic as soft wax. ‘“Tausend Gelehrte—tausend An- 
sichten.” So much so that the public has become more or less consciously 
sceptical and shy of philosophy (‘ philosophiescheu ”), and has fallen back into 
an intellectual slough which is called matter-of-factness. And even among the 
initiated the spectacle is seen of Philosophy receiving a pitiable alms at the 
door of the scientific mansion. 
As a relief from this sluggish scepticism on the one hand and arrogant 
superficiality on the other, Dr. Wagner suggests that every man may be his own 
thinker. ‘Nur was selbst durchdacht ist, hat geistigen Wert . . . Immer und 
ewig ist die Parole: Selbst denken.” This being granted, we are led by the 
author’s lively conversation step by step to the conclusion—for which no 
novelty is claimed—that an unphilosophical science is a contradiction in terms, 
that there can be no wissenschaftliches Denken without a criticism of categories. 
X. 
