The Natural History of the Categories 281 



say that reality has neither forward nor backward refer- 

 ence. So say the idealists in getting thought which is 

 not in time. But be that as it may, we are dealing with 

 experience, though for myself, I must say, thought which 

 looks neither backward nor forward is no thought at all. 



§ 7. The Natural History of the Categories 



Another subtlety might raise its head in the inquiry 

 whether in their origin all the categories did not have their 

 ' natural history.' If so, it might be said, we are bound, in the 

 very fact of thinking at all, to give exclusive recognition to 

 the historical aspect of reality. But here is just the ques- 

 tion : does the outcome of career to date give exhaustive 

 statement of the idea of the career as a whole t There 

 would seem to be two objections to such a view. First, it 

 would be, even from the strictly objective point of view, 

 the point of view of physical science, to construe the thing 

 mind entirely in terms of the behaviour of its stages ante- 

 cedent to the present ; that is, entirely in terms of descriptive 

 content, by use of the categories of retrospective interpre- 

 tation. And, second, it does not follow that because a 

 mental way of regarding the world is itself a genetic growth, 

 therefore its meaning is exhausted in the conditions of its 

 genesis. Let us look at these two points a little more in 

 detail. 



I. A chemist seems justified in looking upon atmospheric 

 air as explained by the formula for a mixture of nitrogen 

 and hydrogen, for the reason, and this is his practical test, 

 that the behaviour of air confirms that view. His confi- 

 dence in his statements of history can only be justified on 

 the ground that present history never contradicts it. But as 



