THE STORY OF NINETEENTH-CENTURY SCIENCE 



brain, and that hearing has likewise its local habitation. 

 Indeed, there is every reason to believe that each form 

 of primary sensation is based on impressions which main- 

 ly come to a definitely localized goal in the brain. But 

 all this, be it understood, has no reference to the higher 

 forms of intellection. All experiment has proved futile 

 to localize these functions, except indeed to the extent 

 of corroborating the familiar fact of their dependence 

 upon the brain, and, somewhat problematically, upon 

 the anterior lobes of the cerebrum in particular. But 

 this is precisely what should be expected, for the clearer 

 insight into the nature of mental processes makes it plain 

 that in the main these alleged " faculties " are not in 

 themselves localized. Thus, for example, the " faculty" 

 of language is associated irrevocably with centres of 

 vision, of hearing, and of muscular activity, to go no 

 further, and only becomes possible through the associa- 

 tion of these widely separated centres. The destruction 

 of Broca's centre, as was early discovered, does not alto- 

 gether deprive a patient of his knowledge of language. 

 He may be totally unable to speak (though as to this 

 there are all degrees of variation), and yet may compre- 

 hend what is said to. him, and be able to read, think, and 

 even write correctly. Thus it appears that Broca's cen- 

 tre is peculiarly bound up with the capacity for articu- 

 late speech, but is far enough from being the seat of the 

 faculty of language in its entirety. 



In a similar way, most of the supposed isolated " fac- 

 ulties" of higher intellection appear, upon clearer anal- 

 ysis as complex aggregations of primary sensations, and 

 hence necessarily dependent upon numerous and scattered 

 centres. Some " faculties," as memory and volition, may 

 be said in a sense to be primordial endowments of every 



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