74 THE POPULAR SCIENCE MONTHLY. 



the normal condition return. It is the same when pathological injuries 

 are healed ; the trouble in the intelligence ceases, and reason comes 

 back. Pathology here, too, furnishes us with a kind of functional 

 analysis and synthesis, just as may be observed in experiments of re- 

 production. Disease, in a word, suppresses the function more or less 

 entirely, by changing more or less completely the texture of the organ, 

 and the cure restores the function by reestablishing the normal organic 

 condition. 



If the manifestations of the brain's functions were the earliest to 

 attract the attention of philosophers, they will assuredly be the last to 

 receive explanation from physiologists. We believe that the progress 

 of modern science allows us now to approach the subject of the phys- 

 iology of the brain ; but, before beginning the study of the cerebral 

 functions, we must clearly understand our point of departure. In this 

 essay, we have attempted to state only one term of the problem, and 

 to show how untenable is the opinion that the brain forms an excep- 

 tion in the organism, and is the substratum of intelligence instead of 

 being its instrument. This idea is not merely an obsolete conception, 

 but an unscientific one, injurious to the progress of physiology and 

 psychology. Indeed, what sense is there in the notion that any appa- 

 ratus of Nature, whether in its lifeless or its living domain, can be the 

 seat of a phenomenon without being its instrument ? Preconceived 

 ideas clearly have a great influence in discussing the functions of the 

 brain, and a solution is combated by arguments used for the sake of 

 their tendency. Some refuse to allow that the brain can be the organ 

 of intelligence, from fear of being involved by that admission in mate- 

 rialistic doctrines ; while others eagerly and arbitrarily lodge intelli- 

 gence in a round or fusiform nerve-cell, for fear of being charged with 

 spiritualism. For ourselves, we are not concerned about such fears. 

 Physiology tells us that, except in the difference and the greater com- 

 plexity of the phenomena, the brain is the organ of intelligence in ex- 

 actly the same way that the heart is the organ of circulation, and the 

 larynx that of the voice. We discover everywhere a necessary bond 

 between the organs and their functions ; it is a general principle, from 

 which no organ of the body can escape. Physiology should copy the 

 example of more advanced sciences, and free itself from the fetters 

 of philosophy that would impede its progress ; its mission is to seek 

 truth calmly and confidently, its object to establish it beyond doubt 

 or change, without any alarm as to the form under which it may make 

 its ajjpearance. 



