68 DOGMATISM AND EVOLUTION 



some wider principle, the series of premises necessarily resting 

 upon some ultimate proposition or propositions, for whose truth 

 no other ground could exist beyond their own immediate clear- 

 ness. This conception of the nature of validity and of rational 

 procedure, as we have already pointed out, was made inevitable 

 for rationalism by the representative theory of ideas. Just be- 

 cause the truth of ideas consisted in their correspondence to the 

 reality which they represented, there could, in the last resort, 

 be no test of truth except intuition. 



Now, so far as his ideal of scientific procedure went, Kant was 

 a thoroughgoing rationalist. He was not as he remarks in the 

 preface to the second edition of the Critique of Pure Reason 

 opposed to the dogmatical procedure of reason, since science 

 must always derive its proofs from pure principles a priori. It 

 is only necessary to inquire in what way, and by what right, 

 reason has become possessed of such principles. Mathematics 

 typified in his mind, as in Descartes's, the ideal of scientific 

 method; and this ideal was further confirmed by the recent de- 

 velopment of mathematical physics. The fact of the existence 

 of a body of a priori judgments he assumed without question. 

 Profoundly as Kant was stirred by the analysis of Hume, Hume's 

 scepticism left him untouched. Human knowledge is so he 

 believed unassailably founded on universal and necessary 

 truths. 



As to the character of these truths, however, Kant had become 

 convinced that the a priori premises on which the sciences are 

 founded must be synthetic propositions. It will be remembered 

 that this was a question on which rationalists had not been agreed. 

 Descartes, to whom the issue had not clearly presented itself, 

 admitted both analytic and synthetic propositions among intui- 

 tive truths. Spinoza, too, had included synthetic propositions 

 as axioms among the first principles of his system. Hobbes and 

 Leibniz, however, had, for differing reasons, made the attempt 

 to base deductive science solely on definitions. Now it was evi- 

 dent to Kant, that this latter procedure was impossible. From 



