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 Amjoelopsis ; 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 aft'ect, 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 clown 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. 



J. A. T. 



THE SCIENTIFIC SPIRIT. 



Studien und Skizzen aus Naturwissenschaft und Philosophie. I. Ueber 

 wissenschaftliches Denken und fiber populare Wissenschaft. By Dr. 

 Ad. Wagner. 8vo, pp. 79. Berlin: Gebrfider 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. 



