52 THE NEW PHYSIOLOGY. 



of this address, is often supposed to express absolute 

 truth. This distinction will not hold. Mathematics 

 confines itself to a world which for the moment may be 

 regarded as empty and void. Physics and chemistry 

 confine themselves to a world which for the moment may 

 be regarded as purely inorganic. It is only for practical 

 purposes that we ever make any of these untrue assump- 

 tions ; and we only make them because one or other of 

 them is good enough for our immediate purpose, and 

 enables us to act. 



This address opened with a question as to what the 

 general aims of scientific endeavour are ; and an exami- 

 nation of the aims of biology has led us up to an answer 

 to the wider question as to the aims of science in general. 

 The answer is that scientific generalisations represent, 

 not reality itself, but only certain aspects of it. They 

 are the tools with which we fashion the world of 

 sensuous appearance, and in the fashioning of it reveal 

 its spiritual reality. They are tools of tremendous 

 power, which, if we do not understand and control them 

 rightly, are apt to turn upon and rend us, body and soul ; 

 but still only tools, each contrived for limited practical 

 purposes with endless human labour and care, and con- 

 stantly being increased in efficiency. We who are more 

 immediately concerned in the making of these tools, or 

 who 'are pioneers or instructors in their use, may often 

 be different persons from the more immediately practical 

 users of them. We may not be manufacturers or en- 

 gineers, sailors or soldiers, farmers or doctors, lawyers 

 or statesmen ; but all are serving the same ends, and all 

 are, or ought to be, concerned in the capacities and limita- 

 tions of the tools they use. We are not a class aloof 



