418 CRITICAL NOTICES : dary importance, thinks M. Binet ; but that is solely because he has eliminated from his analysis attention which is involuntary in perception, voluntary in reasoning. We might compare the series of percepts to those " tapes " frequent in stockbrokers' offices, in which the winner of the Derby is followed by the price of consols, that again by the dividend of the Suez Canal, this by the prospects on the Home Rule Bill, that by the betting for the Oaks, and so on. The thought-series brings these items into connexion by doubling the tape so as to bring the betting on the Oaks in con- nexion with the winner of the Derby, the price of consols with the Home Eule Bill, and so on. It is this doubling, this active rela- tioning of thought and reasoning, which constitutes the main difference in the two functions, and M. Binet has been unfortu- nate in choosing as his type of reasoning the syllogism which for logical purposes supposes all this psychological process of active relationing to be concluded and premisses to follow one another with mechanical regularity. Taking all these divergences into consideration, we must hold that the proposed identification of perception and reasoning is illusory, nor can we look forward, with M. Binet, to any elucida- tion of the reasoning processes from the hallucinations of hypno- tised patients (p. 140). It is true that for his identification he has the weighty authority of Mr Herbert Spencer, but under somewhat different circumstances. We are too apt to forget that the Priuc i]///;-; of Psychology scarcely answers to its title, and deals rather with the principles of evolution as illustrated by the growth of mind. Mr Spencer's object is to prove that his familiar formula about homo- geneity and indefiniteness and the rest applies to all the processes of mind. For this purpose he insists, and has perhaps the right to insist, on any point of resemblance which enables him to con- nect one mental process with another. Besides for philosophical purposes the law of parsimony comes into operation, and a philo- sopher is in the right to minimise his generalisations. But if psy- chology is to become a science, quite as much regard must be paid to the differences in the mental processes as to their simi- larities. The influence of the doctrine of evolution is particularly misleading in this connexion : its assumption of a gradual shading- off of one process into another gives too often encouragement to a somewhat slovenly identification of the two. However identical in germ, they have been differentiated in development. And when we ask by what principle they have been differenti- ated in the past we reach a fundamental difference of standpoint which may perhaps explain and excuse the polemical attitude here taken against M. Binet's book, admirable as it is in so many of its details, and indeed in its general conception, if we judge it merely from its own point of view. In a concluding passage M. Binet recognises that his exposition reduces mind to an associa- tion of images, the only activity recognised being that of the images. Though at times he gives a bare mention to Attention,
