152 DEVELOPMENT AND PURPOSE CHAP. 



world in which it lives and which it takes prima facie as 

 plain reality. We may speak of this as the evaluation of 

 the subjective factor in Thought. In the second place, 

 we must find some elementary data, which at the end of 

 criticism may be taken as a basis of reconstruction, and 

 some method of building upon them. If these data and 

 methods could be taken as final, that is to say, as inde- 

 pendent of any of the limitations affecting Mind, they 

 would be all that we should require. But as we cannot 

 escape from our own minds, as criticism is still a mental 

 process, and the most fully critical method a mental pro- 

 duct, and the most objective c datum ' something that 

 Mind can grasp, it follows that any reconstruction that we 

 can make remains liable to the imputation of relativity, 

 We shall need therefore in the third place a theory of 

 rational proof which will decide on the claims of rival 

 constructions, and furnish a grounded judgment of the 

 final value of our thought-structure. 



Of these three questions, the first two concern the nature 

 and method of reconstruction, the third its final validity. 

 To show how the first two arose in modern thought will 

 therefore suffice for our present purpose, while we may 

 reserve the third for later investigation from a somewhat 

 different point of view, only touching on it incidentally 

 here. 



2. Now, the evaluation of the subjective factor in know- 

 ledge may be fairly regarded as the central contribution of 

 the first movement in modern philosophy from Des 

 Cartes to Kant. Knowledge is the property of a conscious 

 subject. It is conditioned by the character and limitations 

 of its subject, and the problem of its relation to its object 

 at once begins to press. It is here that the 'distinctive 

 features of modern philosophy emerge. Ancient thought 

 had been familiar with the conception of the mind as a 

 structure interacting with objects, and Protagoras if the 

 Theaetetus reports him accurately educed therefrom 

 a sceptical form of relativism, making man the measure 

 of things. Modern thought is an effort to work through 

 relativism to objectivity, by accepting the c moment ' of 



