60 INTRODUCTION 



evidence requires elucidation : the basis of it must be 

 made manifest \ Self-consciousness, then, is really self- 

 consistent only in virtue of its being a definite system, 

 a self-revealing process or development, which contains 

 within itself the ground or reason of its self- consistency, 

 and the ground or reason of existence. Accordingly, to 

 treat it in philosophical investigation as if it were merely 

 superficially self-consistent, as if the law which expresses 

 its whole nature were the law of contradiction, would be 

 to arrive at an empty and abstract result. 



Leibniz, however, while recognizing the inadequacy of 

 the principle of contradiction as thus interpreted, did not 

 clearly enough perceive the reason for this inadequacy. 

 He regarded the principle of contradiction, not as an 

 imperfect interpretation of the one principle of all truth, 

 to be made perfect by further definition, but as an in- 

 dependent principle, adequate to a certain kind of truth, 

 yet requiring to be supplemented by another co-ordinate 

 principle, which should be the standard of another kind 

 of truth. If the principle of contradiction be the sole 

 principle of knowledge, whatever is not self-contradictory 

 is true ; and nothing is true unless it can be shown that 

 it is not self-contradictory. But how are we to determine 

 what is or is not self-contradictory ? According to the 

 Cartesians this is to be done by analytically reducing the 

 doubtful statement to one or more self-evident propo- 

 sitions, or, in other words, by showing that the state- 

 ment is ultimately involved in one or more propositions, 

 of such a kind that their predicate is manifestly contained 

 in their subject 2 . But Leibniz maintains that there are 



the axioms themselves.' Cf. Eraser's ed. of Locke s Essay, vol. ii. 

 p. 267, note. 



1 Cf. Noureaux Essais, bk. iv. ch. n, 14 (E. 379 b ; G. v. 428) : 

 ' As to eternal truths, it is to be noted that at bottom they are all 

 conditional and say in effect : such a thing being supposed, such 

 another thing is.' 



3 According to Leibniz, all true propositions must be such that 

 their predicate is really contained in their subject, although this 

 may not be self-evident. This is simply expressing in another 



