SIR WILLIAM HAMILTON'S PHILOSOPHY, 383 



Still unsolved problems regarding sensation is to be sought as much 

 from physiology as from psychology. I shall say nothing of the 

 assistance which physiology has rendered in narrowing down the con- 

 troversy regarding the origin of the different factors which constitute 

 human knowledge, nor need I indicate the light which it may throw 

 on many peculiarities among the phenomena of human consciousness. 

 Sir William Hamilton himself, by his numerous interesting notes on 

 the physiology of the nerves, has shown the psychological importance 

 of this study ; and in subsequent parts of this criticism we may have 

 an opportunity of noticing the explanation of several phenomena 

 which is furnished by attention to the laws of nervous action. 



Although, therefore, the value of physiology in mental science may 

 be too highly exalted, it is not legitimate to despise its contributions 

 altogether. Its relation to psychology is in fact that of several other 

 sciences whose borders at points unavoidably overlap those of the 

 science of human nature. The science of language, to take an obvious 

 instance, is growing every day into an importance which must be 

 more fully accorded to it as a handmaid to the science of mind ; for 

 in the words which, expressing the most familiar and indispensable 

 ideas, are to be found in all languages, in the nominal and verbal 

 inflections of different tongues, in the manifold grammatical and 

 lexical changes which human speech is everywhere undergoing, there 

 is undoubtedly preserved a record of processes through which the 

 human mind has been developed in pre-historic as well as in historic 

 times, and by a more accurate and extensive study of this record we 

 may be more easily and surely guided to the laws by which the mental 

 development of mankind is regulated. I see no improbability in the 

 prospect of attempts, as definite as those which have been made in 

 favour of physiology, to supersede psychology by comparative 

 philology. It is unnecessary, in further illustration of this subject, to 

 do more than draw attention to the fact, that the most valuable 

 assistance may also be rendered to the science of mind by the general 

 history of the human race as well as by the special history of different 

 departments of human activity, by the natural history of mankind and 

 by those statistics of modern society, the accurate collation of which 

 has become one of the most interesting studies among the facts of 

 human life. 



In connection with the evidence and authority of consciousness we 

 have still to consider Hamilton's doctrine regarding the basis and 



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