208 The two factors of Kno w ledge. CHAP. 



lectual organ, nor, apparently, the rudiments of such 

 an organ, which would enable us to pass, by a process 

 of reasoning, from the one to the other. They appear 

 together, but we do not know why." 



But though all this is totally inscrutable, there 

 are other questions respecting Mind, on which I 

 believe it will be found that the doctrine of Evolution 

 throws much light. 



At an early period, the doctrine that knowledge 

 comes through sensible perception was formulised in 

 the well-known saying : " There is nothing in the 

 intellect but what was previously in the sense." But 

 this, even if true, was evidently an incomplete state- 

 ment; and Leibnitz modified it thus: "There is 

 nothing in the intellect but what was previously in 

 the sense, except the intellect itself." This addition 

 to the old axiom is so self-evident that it may appear 

 scarcely worth making ; but it raises the entire ques- 

 tion of the relation between the two factors of our 

 knowledge, namely, the impressions which come 

 through the organs of sense, and the intellect on 

 which the impressions are made. This is a vast 

 problem, and it is perhaps not too much to 

 say that all philosophical work since the time of 

 Leibnitz has been occupied in approximating to its 

 solution. 



The philosophy of Kant, which its author rightly 

 named the Critical Philosophy, begins with the in- 

 vestigation of this problem ; and its result is briefly 



