128 DEVELOPMENT AND PURPOSE CHAP. 



.given originally in experience. These elements are sub- 

 jected to processes of analysis and synthesis whereby con- 

 tents are formed, which as wholes do not necessarily 

 resemble anything in experience. Thought does not copy. 

 It builds. But it builds only with materials taken from 

 the experienced order, and any apparent concept not formed 

 from such materials is meaningless, and turns out upon 

 examination to be no concept, but either a form of words 

 or a mistranslation of something else. To this extent the 

 content of the wildest imagination is related to and may 

 fae compared with experience. 



But the concept of pure imagination and the concept of 

 logic differ vitally in one respect. Both exist as contents 

 of that mental state which we may call conception. But 

 the imaginary concept, at least so far as it is recognised as 

 imaginary, is satisfied, if I may so express it, with its own 

 existence. The logical concept, on the other hand, involves 

 a reference to some further reality. Now this further 

 reality might be only another concept or system of concepts 

 existing in my own mind or in that of other people. But 

 it may also be Reality in the sense of that which is con- 

 tinuous and of one texture with experience the Whole 

 which is given fractionally in present experience. Now 

 concepts in general are formed, as has been said, from this 

 Reality, and the function of the concept in knowledge 

 and this function is what distinguishes the logical concept 

 is to gather together related elements of Reality. The 

 logical concept then has an implied reference to Reality, 1 

 and when this reference is justified by the existence of 

 something Real that corresponds to it, the concept may be 

 said to have Validity. 2 



1 Thus the concept may be regarded as embodying the material of an 

 existential judgment, which only requires to be affirmed to be definitely 

 asserted of reality. 



2 That is to say, a concept A is valid if the judgment * A exists ' is true. 

 But may not a concept be valid on any other condition ? The point 

 raises the most difficult question of conceptual logic, the validity of 

 "* imaginary expressions,' concepts to which nothing in experience con- 

 forms, but which are formed by logical processes and can be used without 



allacy in calculation. It seems impossible to deny all validity to such 

 conceptions, but I think it may be said that their validity depends 



