48 COSMIC PIIILVSOPHY. [pt. i. 



deny all that the doctrine of relativity explicitly denies, 

 but which differ from the doctrine of relativity in ignoring 

 what the latter implicitly asserts, the Leibnitzian theorem 

 was again taken up by Kant, who made it his own by his 

 manner of illustrating it, and whose arguments on this topic 

 still carry conviction to the minds of many able metaphysicians. 

 The immense importance of Kant's views makes it desirable 

 for us to give them some farther consideration than is im- 

 plied in merely stating them. 



In the first place, it must be borne in mind that Kant 

 maintained, no less stoutly, and perhaps no less consistently, 

 than Hume, the doctrine of the relativity of all knowledge. 

 As Mr. Lewes truly observes, "the great outcome of the 

 Kritik was a demonstration of the vanity of ontological specu- 

 lation." Kant would have repudiated Schelliir; and Hegel, 

 as he did in fact openly repudiate the claims of Fichte to be 

 considered his legitimate successor and expounder. It was 

 Kant who first showed that every hypothesis which we can 

 frame respecting the Absolute, the Infinite, the First Cause, 

 or the ultimate essences of things, must inevitably commit 

 us to alternative impossibilities of thought. It was Kant 

 also who showed psychologically, from the necessary coopera- 

 tion of subject and object in each act of cognition, that a 

 knowledge of the pure object as unmodified by the subject is 

 for ever impossible. Kant held that a phenomenon, inas- 

 much as it is an appearance, presupposes a noumenon — a 

 thing which appears, — but this noumenon, which is a neces- 

 sary postulate, is only a negation to us. It can never be 

 positively known ; it can only be known under the conditions 

 of sense and understanding, ergo, as a phenomenon. " And 

 accordingly," says Kant, " though the existence of an external 

 world is a necessary postulate, its existence is only logically 

 affirmed." Of its existence out of relation to our conscious- 

 ness we can know nothing ; and it consequently appears that 

 ' we can never predicate of our knowledge that it has objec- 



