i 4 DEVELOPMENT AND PURPOSE CHAP. 



endeavour to seize on such salient points as may serve to 

 determine its trend and measure the length and direction 

 of the path along which it has moved. 



6. tip to this point, as has been remarked in the Intro- 

 duction, our method is purely empirical. We have simply 

 to analyse and compare the operations and achievements of 

 mind in successive phases, to show how one phase may be 

 conceived as issuing from another, and to indicate the 

 nature of the changes successively introduced. But par- 

 ticularly as we reach the higher phases we shall see that 

 another set of questions underlies our whole enquiry. 

 When for example we deal with the emergence of rational 

 method, as in science and philosophy, we shall have to take 

 account of the claim of such a method to yield truth. This 

 claim is an integral part of this particular phase of develop- 

 ment, and we shall not be able to understand that phase or 

 place it in due relation to others without enquiring into 

 the nature of rational method and thus opening up the 

 question of the validity of thought. Similarly on the 

 ethical side we shall come upon theories of conduct or of 

 human well-being which we shall not be able to interpret 

 without opening questions as to the meaning of such terms 

 as good and bad, right or wrong. It is true that we might 

 keep to a purely historical method by merely recounting 

 the opinions which men have held or the methods which 

 they have in fact pursued. But it is clear that our con- 

 ception of a given intellectual movement will differ radi- 

 cally according as we hold that it is a movement towards 

 truth or towards error, or again towards a goal of real value 

 or to one of no greater account than any other. Thus if 

 our object be not merely to record the successive phases 

 in the movement of mind but to appreciate the direction 

 and magnitude of that movement and this is the object 

 which I would propose for the enquiry it is clear that we 

 have to go outside the purely historical method of treat- 

 ment ; we must apply a philosophical theory of the basis of 

 rational belief and action in order that we may take stock 

 of the position at which we have arrived. If, for example, 

 we can satisfy ourselves that we have some knowledge of 

 reality, grounded, let us say, on the methods of science, 



