PSYCHOLOGY Ixxvii 



on such knowledge as he possessed of the physiology of the 

 nervous system. Doubtless that knowledge was scanty and 

 almost evanescent : even in our time physiology is only 

 just beginning to reach a development sufficient for the 

 foundation of a thoroughly scientific psychology. Lamarck 

 went far in the direction of materialism, though the 

 imperfect physiology of his day led him into a materialism 

 almost as crude as was the spiritualism of his day. He 

 denied the existence of the " peculiar entity called mind " 

 (esprit). " In this factitious entity," he continues, " which 

 is not like anything else in nature, I see a mere invention for 

 the purpose of resolving the difficulties that follow from 

 inadequate knowledge of the laws of nature." Mental mani- 

 festations are simply " effects " of cerebral processes, not 

 manifestations of a separate entity. He could hardly have 

 expressed it better. The whole of Lamarck's psychology is 

 thus reduced to an investigation of the physical or cerebral 

 processes which are correlated with mental processes. 



So far, Lamarck's method is admirable. His classification 

 of the functions of the nervous system is also excellent : he 

 says there are four : (1) the production of muscular move- 

 ment, (2) of sensation, (3) of emotion, (4) of intellect ; a 

 classification which is obviously in close correspondence with 

 the modern tripartite division of mind. More especially is 

 he to be praised for the prominence which he gives to emo- 

 tion : — the importance of which has always been grotesquely 

 underestimated or altogether overlooked by the metaphysical 

 schools of psychology. 



But, having said so much, I have said about all that can 

 be said for Lamarck's psychology. He wished to base his 

 psychology on the physiology of the nervous system : and 

 so far he was right. But his knowledge of that physiology 

 was worse than non-existent : his ideas on the subject were 

 extensively and radically erroneous ; the greater part of his 

 positive statements are altogether untrue. 



Lamarck held that the nervous ^stem consisted of three 

 kinds of substance, the medullary pulp, the aponeurotic 



