THE FIELD OF LOGIC 321 



tions. They have, to my mind, the greatest importance, and due 

 weight has, as yet, not been given to them. To one at all committed 

 to a unitary and evolutionary view of the world, it must indeed seem 

 strange if thinking itself should not be the result of evolution, or that, 

 in thinking, parts of the world had not become adjusted in a new- 

 way. But while I am ready to admit this, I am by no means ready to 

 admit some of the conclusions for logic and metaphysics which are 

 often drawn from the admission. Just because thought, as a product 

 of evolution, is functional and judgment instrumental, it by no means 

 follows that logic is but a branch of biology, or that knowledge of the 

 world is but a temporary adjustment, which, as knowledge, might 

 have been radically different. In these conclusions, often drawn with 

 Protagorean assurance, two considerations of crucial importance 

 seem to be overlooked, first, that adaptation is itself metaphysical in 

 character, and secondly, that while knowledge may be functional and 

 judgment instrumental, the character of the functioning has the 

 character of knowledge, which sets it off sharply from all o^her 

 functions. 



It seems strange to me that the admission that knowledge is a 

 matter of adaptation, and thus a relative matter, should, in these 

 days, be regarded as in any way destroying the claims of knowledge 

 to metaphysical certainty. Yet, somehow, the opinion widely prevails 

 that the doctrine of relativity necessarily involves the surrender of 

 anything like absolute truth. " All our knowledge is relative, and, 

 therefore, only partial, incomplete, and but practically -trustworthy/' 

 is a statement repeatedly made. The fact that, if our development 

 had been different, our knowledge would have been different, is 

 taken to involve the conclusion that our knowledge cannot possibly 

 disclose the real constitution of things, that it is essentially condi- 

 tional, that it is only a mental device for getting results, that any 

 other system of knowledge which would get results equally well 

 would be equally true; in short, that there can be no such thing as 

 metaphysical or epistemological truth. These conclusions do indeed 

 seem strange, and especially strange on the basis of evolution. For 

 while the evolutionary process might, conceivably, have been dif- 

 ferent, its results are, in any case, the results of the process. They 

 are not arbitrary. We might have digested without stomachs, but 

 the fact that we use stomachs in this important process ought not to 

 free us from metaphysical respect for the organ. As M. Rey suggests, 

 in the Revue Philosophique for June, 1904, a creature without the 

 sense of smell would have no geometry, but that does not make 

 geometry essentially hypothetical, a mere mental construction; for 

 we have geometry because of the working out of nature's laws. 

 Indeed, instead of issuing in a relativistic metaphysics of knowledge, 

 the doctrine of relativity should issue in the recognition of the finality 



