588 CRITICAL NOTICES :

with Prof. James, holding it to be a complex of afferent sensa- tions. The next chapter treats of the " Physical Basis of the Higher Faculties". At the beginning an excellent account is given of how physiological psychology should unite physical and mental science. The chapter is largely occupied with memory, but no mention is made of the experiments of Ebbinghaus and others. Prof. Ladd holds that the inertia of the nervous system furnishes, " in part, the necessary conditions of conscious acts of memory," but thinks judgment, reasoning, &c., can have no physical con- comitants. Thus he says (p. 545) : " From its very nature that marvellous verifying actus of mind in which it recognises itself as the subject of its own states, and also recognises the states as its own, can have no analogous or corresponding material sub- stratum ". The eleventh and last chapter of this section is on " Certain Statical Eelations of the Body and Mental Phenomena," and treats of age, sex and temperament. It is not easy to draw a sharp line between physiological psychology, on the one hand, and anthropology, sociology and philology, what the Germans call " Volkerpsychologie," on the other. Mr. Galton's name is not mentioned in the book, nor does it touch work such as that associated with the names of Steinthal and Lazarus. It must have been difficult to prepare a book on physiological psychology without making mention (beyond a brief account of aphasia from the physiological side) of language. Abnormal states of con- sciousness are expressly excluded. This was perhaps necessary, owing to the limits of the work ; but it is none the less a pity, as disturbances of consciousness are of the utmost interest to the psychologist, both in themselves and owing to the light they throw on the normal workings of the mind. Prof. Ladd classes sleep and dreaming, in which a third of healthy life is passed, under abnormal states of consciousness. In concluding this section, Prof. Ladd gives " five great groups of correlations between body and mind". Proposition (4) must, however, be given a somewhat forced interpretation, in order to bring it into harmony with views expressed elsewhere in the book. The propositions are : "(1) The quality and intensity of the sense-element in our experience is correlated with the condition of the nervous system as acted on by its appropriate stimuli. (2) The combination of our conscious experiences is correlated with the combination of the impressions made upon the nervous system. (3) Those phenomena of consciousness, which we designate as 'memory' and 'recollection,' are correlated with the molecular constitu- tion and tendencies of the elements of the nervous system. (4) The course of thought, and all the higher forms of self-conscious experience, are corre- lated with the condition of the nervous centres. (5) The statical condition of the body and the general tone or colouring of conscious experience are correlated."