10 THE NEW PHYSIOLOGY. 



conceptions of matter and energy to physics, or of the 

 atom to chemistry. Let me try to give more definition 

 to this conception. A living organism is distinguished 

 by the fact that in it what we recognise as specific struc- 

 ture is inseparably associated with what we recognise as 

 specific activity. Its activity expresses itself in the 

 development and maintenance of its structure, which is 

 nothing but the expression of this activity. Its identity 

 as an organism is not physical identity, since from the 

 physical standpoint the material and energy passing 

 through it may be rapidly changing. In recognising it as 

 an organism, we are applying an elementary conception 

 which goes deeper than the conceptions of matter and 

 energy, since the apparent matter and energy contained 

 in, or passing through, or reacting with, the organism 

 are treated as only the sensuous expression of its exis- 

 tence. Even the environment is regarded as in organic 

 relation with the organism, and not as a mere physico- 

 chemical environment. It follows that for biology 

 we must clearly and boldly claim a higher place than 

 the purely physical sciences can claim in the hierarchy 

 of the sciences — higher, because biology is dealing with 

 a deeper aspect of reality. It must also be the aim of 

 biology gradually to penetrate behind the sensuous veil 

 of matter and energy which at present seems to obscure 

 the organic world at all points. 



Let us now see how the conception just defined can 

 be used as a scientific working hypothesis. In accord- 

 ance with it any form of physiological activity is pre- 

 sumably related essentially, and not accidentally, to 

 the other details of activity and structure in the same 

 organism. Stated generally, therefore, the problem of 



