v EVOLUTION AND TELEOLOGY 339 



treasure digger applies. The gold was not there, but the 

 digging itself produced golden value in the soil. There 

 are features in the history of discovery which suggest an 

 analogous truth in this relation. By patient work we 

 build, but not as we planned. If this is true of the search 

 for the philosopher's stone, may it not be as true of the 

 search for any completeness of understanding ? 



Before yielding to this doubt, we shall do well to look 

 more closely at the actual course of thought. We have 

 spoken of the solid fabric already reared as having intrinsic 

 value, but when we look at the actual structure of know- 

 ledge, even of the physical science, nay, even under certain 

 aspects of Mathematics itself, this solidity is not so easily 

 to be seen. Everywhere, as we approach the wider and 

 deeper conceptions conceptions which make up the very 

 tissue of our experience, such conceptions as Space, Time, 

 Number, Matter, Force, Energy, Life, Thought, Con- 

 sciousness, Morality we enter a region, not of rocklike 

 stability, but of a fluidity of which the best that we can 

 hope is that it is the fluidity of growth. The advance of 

 experience does not merely add grain after grain to a heap 

 that is accumulated once for all. There is addition, but 

 with addition there is also constant modification, and few, 

 if any, are the truths of which we can say with confidence 

 that they can never be modified. Perhaps there are none 

 even in Arithmetic of which the total interpretation may 

 be regarded as finally and irrevocably fixed. The advance 

 of knowledge is a process of modifying conceptions. But 

 if this is so, what validity, it may well be asked, attaches 

 to the conceptions already formed, and to the thought 

 which engenders them ? If rational methods do not yield 

 us truth, what do they yield us whereby we may put confi- 

 dence in them? The answer is hard to find unless we 

 remember that modification is necessary to growth, and 

 conceive reason, accordingly, as an impulse towards har- 

 mony which, however incomplete at any given time, is 

 always moving in the right direction. If this conception 

 be admitted, it becomes intelligible that a method should 

 be valid though its immediate result does not possess final 

 truth. The validity of the method rests in this, that it is 



