82 MENTAL EVOLUTION IN MAN. 



reasoning requires to be taken on the solid basis of a pro- 

 position. But by frequent habit the thinking faculty ceases 

 to be thus restricted : it passes, so to speak, from one end of 

 the chain to the other without requiring to pause at every 

 link : for its original stepping-stones it has substituted a 

 bridge, over which it can pass almost at a bound. Or, again, 

 to change the metaphor, there arises a method of short-hand 

 thinking, wherein even the symbols of ideas (concepts) need 

 no longer appear in consciousness: judgment follows judgment 

 in logical sequence, yet without any articulate expression by 

 the verbiim mentale. This, I say, is a matter of fact which it 

 appears to me a very small amount of introspection is enough 

 to verify. On reading a letter, for instance, we may instan- 

 taneously decide upon our answer, and yet have to pause 

 before we are able to frame the propositions needed to 

 express that answer. Or, while writing an essay, how often 

 does one feel, so to speak, that a certain truth stands to be 

 stated, although it is a truth which we cannot immediately 

 put into words. We know, in a general way, that a truth 

 is there, but we cannot supply the vehicle which is to 

 bring it here ; and it is not until we have tried many devices, 

 each of which involve long trains of sequent propositions, 

 that we begin to find the satisfaction of rendering explicit in 

 language what was previously implicit in thought. Again, 

 in playing a game of chess we require to take cognizance of 

 many and complex relations, actual and contingent ; so that 

 to play the game as it deserves to be played, we must make 

 a heavy demand on our powers of abstract thinking. Yet in 

 doing this we do not require to preach a silent monologue as 

 to all that we might do, and all that may be done by our 

 opponent. Lastly, to give only one other illustration, in 

 some forms of aphasia the patient has lost every trace of 

 verbal memory, and yet his faculties of thought for all the 

 practical purposes of life are not materially impaired. 



On the whole, therefore, I conclude that, although language 

 is a needful condition to the original construction of con- 

 ceptional thought, when once the building has been completed, 



