ch. in.] THE TEST OF TRUTH. 51 



can by its reactions determine it in other cases. TTaving 

 experience of an acid and an alkaloid, each apart from the 

 other, he can separate them when finding them combined in 

 a salt, or he can combine them when he finds them separate. 

 His analysis and synthesis are possible, because he has else- 

 where learned the nature of each element separately. But such 

 analysis or synthesis is impossible with the objective and sub- 

 jective elements of thought. Neither element is ever given 

 alone. Pure thought and pure matter are unknown quan- 

 tities, to be reached by no equation. The thought is neces- 

 sarily and universally subject-object ; matter is necessarily, 

 and to us universally, object-subject. Thought is only called 

 into existence under appropriate conditions ; and in the objec- 

 tive stimulus, the object and subject are merged, as acid and 

 base are merged in the salt. When I say that the sensation 

 of light is a compound of objective vibrations and retinal 

 susceptibilit} r , I use language which is intelligible and ser- 

 viceable for my purpose ; but I must not imagine that the 

 external object named vibration is the Ding an sich, the pure 

 object out of all relation to sensibility ; nor that the retinal 

 susceptibility is pure subject, involving no vibratory element. 

 Kant himself would assure me that the vibrations were as 

 subjective as the susceptibility. Indeed, seeing that he 

 denied altogether the possibility of a knowledge of pure 

 ?bject, the Ding an sich, it was a violent strain of logic to 

 conclude that in thought he could separate this unknowable 

 object from the subject knowing it." 1 



A violent strain of logic it was, no doubt. After proving, 

 almost to superfluity, that subject and object are inseparably 

 united in each act of cognition, and after triumphantly using 

 this fact against the ontologists who pretended to a knowledge 

 jf the objective reality in itself, Kant turns around and tells 

 us that we may after all acquire a knowledge of the subjective 

 reality in itself! Though we can never determine what the 

 1 Lewes, History of Philosophy, 3rd edition, vol. ii. p. 483. 



E 2 



