344 PHILOSOPHICAL THOUGHT. 



34. Be this as it may, the philosophy of Kant has, as the 



Kant's 



philosophy nineteenth century advanced, been more and more con- 



a central 



point sidered as a central point in the development of modern 

 thought. Especially so far as the problem of knowledge 

 is concerned, we find that the different sides which this 

 problem presented to different thinkers in different 

 countries were already explicitly given or implicitly 

 contained in the writings of Kant. Here his lasting 

 influence may be shown in the great number of pre- 

 liminary and subsidiary problems which he formulated, 

 and into which he divided the main problem itself ; 

 not least also in the large array of new terms which 

 he introduced for the definition of these problems. 

 Through them he succeeded in fixing the attention 

 of his own and subsequent ages. For our present pur- 

 pose it may be convenient to gather this formidable 

 body of thought under three headings. 



35. First, Kant gave to the ancient theory of the Ee- 



Belativity 



of Know- lativity of Knowledge a new form and expression. He 

 did away with the primary (mathematical) properties 

 of external things, which even Locke considered to 

 afford a real, not merely a phenomenal, knowledge of 

 things. He showed that these properties, which refer 

 to the existence of things in time and space, are not 

 less dependent on the nature of the human mind than 

 the so-called secondary properties which depend on 

 the nature and operation of our several sense-organs. 

 Also he showed that to the forms of time and space 

 belonged a special definiteness, that the conceptions 

 of extension and duration, and the properties of things 

 connected therewith, possess a greater convincing evi- 



