APPENDIX I. 



NOTICES OF BOOKS. 



Lectures on Human and Animal Psychology. By Wilhelm Wundt (translated from second 

 German edition by J. E. Creighton and E. B. Titchener). London : Swan Sonnenschein, 

 1894. 



The particular interest of this book is, that appearing so long ago as 1862, it is still in 

 touch with the problems that are interesting us to-day as physiological psychologists. It is 

 true that Professor Wundt rewrote it in great part in 1892, but the general trend of the work 

 is the same as in the original, and it is very remarkable to see how what in 1862 was avowedly 

 a programme is now in 1895 a working class-book of experimental psychology. Wundt 

 himself says (preface to second edition) that " the physiological correlates of psychical processes " 

 are less developed here than in the Physiologischen Psychologic, and that he devotes few words 

 to subjects elsewhere discussed in detail, and gives more attention to others less prominent, 

 especially in the last-named work. On this account the Human and Animal Psychology 

 must not be taken as superseding the Physiological Psychology for English readers— hardly- 

 even as an introduction to it (as seems intended in the translators' preface). We should our- 

 selves in preference turn to the larger work for a general presentation of any subject. 



In view of the development of experimental psychology, it is interesting to note that 

 \\ undt has rewritten the chapters on Sensation, where laboratory work comes so much into 

 evidence, while other more theoretical parts, e.g., his theory of sense-perception by spatial 

 localisation, have only undergone revision. And the new section is that on Will, Attention, 

 Apperception, Association, so familiar to us all, as names, under Wundt's superscription. A 

 short summary of the contents of the book, pausing at one or two points of present interest, 

 may best indicate to what extent Wundt is the representative of " the new psychological move- 

 ment " (translators' preface). 



In 1862 it really was necessary to vindicate the claims of Psychology to be regarded as 

 one of the natural sciences, independent of metaphysics. Wundt had to teach that not 

 metaphysical questions, but " the uniformities of relation in the phenomena presented to our 

 observation," are its subject-matter, and he was probably the first to assert that experimental 

 psychology makes possible for philosophy that "absolutely impartial consideration of ex- 

 perience " in which alone metaphysical problems can hope for solution. On the other hand, 

 he expressly points out that it is not merely chemical and physical investigation of the brain, 

 but experimental observation of the mind itself, which must be the starting-point of psychology. 

 [It will be remembered that Wundt uttered a strong protest last year ( Ueb. psychische Causdlitat, 

 etc. , / 'hi/. Stud. , xi. ) against the ' ' experimental psychology which reduces psychological processes to 

 anatomical elements, until it almost appears as an appendix to muscular contraction ".] Yet 

 the nature of psychological facts is such that only the mental phenomena which are directly 

 accessible to physical influences can be made the subject-matter of experiment, i.e., the 

 organs of sense and movement which are functionally related to mental processes. Hence it 

 comes about that every psychological experiment is at the same time physiological, and it is 

 this ncio method of experiment "which characterises the modern treatment of psychology. The 

 image of the external object or idea is the proper starting-point of a psychological analysis. 

 Under Ideas, Wundt includes, (1) sense-perceptions, which depend upon direct excitation of the 

 organs of sense; (2) memories of such sense-perceptions ; (3) images of fancy. He protests 

 against the separation of "ideas," as images of memory and fancy, from "perceptions," as 

 direct effects of sense-impression. No essential psychological difference can be discovered 

 between them, while sense-perceptions themselves might well be taken for illusions of sense. 

 The first step in analysis must be to reduce the Idea to its simple constituent elements, or 

 sensations. Sensations again have two properties, (a) strength or intensity, (b) quality. 

 Neither of these can exist in the absence of the other, but they can be varied independently. 



Starting with intensity we have first to find a measure of quantitative difference 

 between sensations, and secondly the relation between stimulus and sensation. Wundt's 

 account of Weber's Law, as formulating the latter, is clear and instructive, although based, 

 in this work, on the least exact method of discrimination, i.e., that of minimum perceptible 



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