222 MENTAL FACULTIES sec. 



them in relation to and in conjunction with new external 

 influences at a given moment for the best advantage of the 

 whole organism. 



Keflex Action 



The starting-point of the evolution of all mental faculties 

 must be sought in reflex action. The lower animals are in the 

 scale of mental evolution, so much the more do they respond 

 to the outer world by reflex action — the lowest perhaps act 

 only in this way : every stimulus which reaches the animal 

 calls forth directly and at once a movement or an action. The 

 more highly a central nervous system, a brain, is developed, 

 so much the more is the sphere of reflex action restricted, so 

 much the more can experiences and faculties be accumulated 

 and transmitted, so much the less will the animal react 

 directly to each stimulus, so much the more will it draw 

 conclusions from that experience — act with reflection. 



Thus the more highly the brain is developed, so much the 

 more firmly stands the organism when confronted with the 

 manifold claims of the outer world ; and conversely, the more 

 manifold the claims to which its conditions of life expose it, 

 the more perfect must be the faculties of its brain. 



When our brain is not healthy, or when our general state 

 of health is imperfect — if we are merely, for instance, suffering 

 from a disordered stomach — the brain no longer works properly, 

 the regular relation between the experiences stored up in it 

 ceases, reflex action again results from stimulation which 

 would otherwise not call forth a direct response. The person 

 is irritable, and behaves unsuitably — after the manner of 

 unreasoning animals — he acts involuntarily.^ 



^ It follows from the above that no fundamental distinction exists between 

 voluntary and involuntary action. In this sense I expressed myself as early as 

 1873 :— 



" By 'will' I understand the release, as the effect of some stimulus, of a portion of 

 the powers which are accumulated in the brain cells, existing in a condition of tension, 



