MancJiester Memoirs, Vol. xlii. (1898), No. \%, 35 



speak the word thus perceived some further psychical act 

 is necessary ; and the neural events which form the basis 

 of this seem to be carried out by the " association " fibres 

 which pass from the visual area of the occipital cortex to 

 the other units in the area in the angular gyrus, and by 

 those other units. We have here, then, an instance of at 

 least two stages of psychical differentiation. And I might 

 quote other instances. 



I am aware that what I have just said is psychologi- 

 cally vague and imperfect. I do not pretend that it is 

 anything more. But I think I may venture to say that, 

 imperfect as it is, it seems to open up the possibility of our 

 gaining, perhaps at no distant date, clearer knowledge. If 

 I have carried you with me in my earlier arguments, we 

 have gained this position, that in the visual neural chain 

 from the retina to the occipital cortex, through the action 

 of unit on unit, neural events in some way or other give 

 rise to visual sensations. Somewhere in this chain the 

 psychical threshold is distinctly passed ; . the neural 

 event, the neural "thing" gives rise to, is accompanied by, 

 manifests itself through conscious sensation. I am pur- 

 posely vague in the use of words to denote the bond 

 between the two. Nevertheless, the psychical event, so far 

 as we can see, is commensurate in magnitude with the 

 neural event, follows it as effect follows cause. But if 

 particular structures, particular units are thus specially 

 associated with the simple elements of psychical life, 

 namely with sensations, it is not too much to conclude 

 that the mere complex psychical factors are similarly 

 associated with particular structures, and that in some 

 such way as the initial purely physical effect of light on 

 the front part of the cone, by means of successive 

 differentiations of that initial effect, through a chain of 

 units gives rise to the undeniably psychical effect, so by 

 successive differentiations through complex chains of 



