126 THE GRAMMAR OF SCIENCE 



missures with psychical action. Destroy a commissure 

 and a man may understand language, but have lost the 

 link to connect the stored impresses of word -meanings 

 with the organ that controls word-sounds ; he suffers from 

 aphasia. Destroy other commissures and other groups of 

 stored impresses may disappear, conscience and the moral 

 sense may become extinct. The psychic is closely allied 

 with the physical, the individuality with what admits of 

 mechanical description. Free-will and consciousness are 

 associated with the interval between sense-impression and 

 exertion, the physical of the outside world becomes the 

 physical of the inner world (p. 65); it is the play of the 

 individuality, of a brain the product of a certain heritage, 

 a certain training, a certain experience. Had we know- 

 ledge enough we can hardly doubt that all this brain 

 action might be described " mechanically." This would 

 not in the least explain the psychic side of the brain- 

 motions, but it would show free-will making no breach in 

 mechanical routine, volition no arbitrary bringing into 

 play of " vital forces " but the introduction into the " outer 

 world " of the action of an " inner " mechanism, the in- 

 dividuality. I act as I do, because I am I, and that 

 wonderful psychic " I," built up of heritage, training, and 

 experience, is associated with a physical " I " built up at 

 the same time, a wonderful " mechanism," which represents 

 it on the physical side. Is there such a thing as free- 

 will ? Certainly, if free-will means acting in accordance 

 with the character, the individuality of the ego. Does 

 free-will connote a breach in mechanical causation, in the 

 law of motion or the principle of energy .? We have no 

 reason to suppose it does, for the interval between sense- 

 impression and exertion — the thought- and consideration- 

 interval — is filled by the play of the physical brain, the 

 marvellous complex upon which no element of race, of 

 ancestry, of education or of experience has failed to leave 

 a more or less indelible impress. It is the physical 

 mechanism corresponding to the psychic individuality, 

 which makes necessity and free-will one and the same 

 thing. But the " necessity " of mechanism is no categorical 



