w. WUNDT'S LOGIK, n. 461 corresponds to Psychophysics in its strictest sense : the two latter cover rather the ground of Experimental Psychology. The former therefore is naturally devoted to a short account of Fechner's well-known methods and laws. A good example of the second is found in Wheatstone's discovery of his explanation of the laws of binocular vision. The last is concerned with problems of which an example may be found in the determination of the length of time required for a reaction to any stimulus, for recognising an object whether familiar or not, and so forth. After these direct inquiries into the elementary phenomena of the normal mature mind, follows a discussion of the resources at our disposal for considering, by means of Comparative Methods, the more abnormal phenomena. This inquiry is divided into four main sections : viz., the comparative examination of other intelligent creatures of a lower order (e.g., the brutes as treated by Sir J. Lubbock) ; the psychical characteristics of infants and children ; the phenomena of disturbed understandings, or those which have never been developed (e.g., the insane, the idiot, and the savage) ; and, lastly, those finer distinctions which present themselves as characteristics of whole races, and which may be regarded as a sort of international Psychology. These four fields of inquiry are classed together under the head of Comparative Methods of Psychology. Each admits again of a further twofold division in respect of the method which is to be applied to it, >:>z., the > ml ! >: Ulnal for the generic method. The individual method examines the psychical characteristics of an individual or of any such group of allied individuals as may, for purposes of study, be reckoned as a unit. This inquiry for various reasons has rather an observational than an experimental character. The generic method seeks to detach some single psychical function, or con- nected group of such functions, in order to test its nature and development over a wide range of observation. Both these methods have to depend in actual practice upon the same general logical operations as we have to work with w r hen engaged in scientific observation elsewhere; viz., partly on what Prof. Wundt calls the methods of Agreement and Difference, and partly on those of Combination and Separation. The next main division to the Comparative is found in the Historico-psychological Method, which is of course nothing but an extension of the comparative method by its application to past time. The history which is thus demanded is naturally of a very special description. From the main stream of what con- stitutes the bulk of the science for the general student it has to select, say, the history of a word and its implied psychological interpretation ; the history of a belief, of a practice, and so on. The principal special applications of this department of study which have hitherto been prosecuted to any good purpose seem to be the comparative sciences respectively known as those of Philology, Mythology and Ethics.
