326 DEVELOPMENT AND PURPOSE CHAP. 



The denial of purposive causation, therefore, is not sug- 

 gested but repelled by general experience, and owes its 

 existence only to the theory that everything must act by 

 mechanical laws. But this theory is a pure assumption, 

 which derives its apparent cogency from confusion with the 

 quite different principle that everything must act in accord- 

 ance with some law. The leading mechanical principles I 

 take to be adequately proved for mechanism, and, therefore, 

 for any structure which is purely mechanical. Now the 

 organism is a physical structure, but to assume that all its 

 actions conform to mechanical laws is to assume that it is a 

 physical structure only. Consciousness directly informs 

 us that it is more than this that it is what we called in 

 Part I. Chapter II. a psycho-physical whole. How far the 

 psychical elments in it, which our account has led us to 

 conceive as activities constantly correlating the actions of 

 its different parts, actually causes the reaction of these parts 

 to diverge from the line that they would follow in accord- 

 ance with purely mechanical laws, is a question which is to 

 be settled entirely without prejudice by inductive argu- 

 ment. This argument shows, in fact, that psycho-physical 

 wholes differ in their behaviour from purely physical 

 systems in direct proportion to the development of the 

 psychical element within them. As against the obvious 

 inference from this argument, the mechanical view can only 

 maintain the bare possibility that there might be a 

 mechanism so constructed as to yield all the varying adapta- 

 tions of the living being. This is a consideration to which, 

 in view of the radically different character of known 

 machines, very little weight would attach, but for the diffi- 

 culty of the supposed breach of continuity involved in 

 purposive action. But there is no breach of continuity. 

 Purposive activity, i.e. the conditioning of the action of 

 each part of a system by the causal tendency of the con- 

 figuration as a whole, is the characteristic mode of reaction 

 of certain structures those which we call psycho-physical. 

 Qua physical this structure tends to act in accordance with 

 mechanical laws, but this action is modified by the condition 

 mentioned, which is the psychical element of the whole in 

 operation. If a body impinges on an arrangement of 



