334 THE PHILOSOPHY OF BIOLOGY 



extent of the changes that occur in the other parts of 

 the system. 



The organism is a centre of continuous action. 



It is first of all a part of nature in which energy- 

 transformations continually take place — a description 

 which applies equally well to plants and animals. It 

 is only when we attempt to seek an inorganic system 

 to which this definition would apply that we find how 

 well it differentiates the organic from the inorganic. 

 An inorganic system which transforms energy is either 

 one which tends continually towards stability, or it is 

 a machine made by man for a definite purpose, and it 

 is therefore a system involving a teleological idea. An 

 organic centre of action is one in which energy-trans- 

 formations proceed without cessation. 



In the plant organism the energy-transformations re- 

 present, with the exception of the reproductive processes, 

 the whole activity of the organism. In the animal organ- 

 ism they are accessory to regulated and purposeful motile 

 activity, that is, muscular action. The obj ect of this mus- 

 cular activity varies with the stage of evolution attained 

 by the animal. Its sole object in the lower animal is 

 that of individual or racial preservation. Living in an 

 organic and inorganic environment which is always 

 hostile and tends continually towards its destruction, 

 the whole activity of the organism is directed to the 

 attempt to master this environment : it struggles for 

 its individual existence, and that of its offspring. The 

 activities of man are also these, but they are more than 

 these, for, knowing that physical processes tend con- 

 tinually towards inertia, he seeks to control these 

 processes, and to preserve the instability of nature on 

 which the possibility of further becoming depends. 



The activity of the organism, whether it be the 

 energy-transformations of the plant or the motile 



