I FUNDAMENTAL CONCEPTS 17 



other in every case of causation like two opposing forces. 

 This logical precision immediately had the effect of making 

 it impossible to understand how the one passed into the 

 other in actual causation. The efficient activity, which 

 had of old been construed on the analogy of our muscular 

 activity, was therefore resorted to in order to supply the 

 explanation. As the muscular movement produces ex- 

 ternal action, so material cause was supposed to produce 

 a material effect. Even then the mind found it difficult 

 to realise the passage from the one to the other. Every 

 causation seemed to imply some action at a distance, 

 unless cause and effect were in absolute contact. But we 

 know that there is no such thing as absolute contact even in 

 the elements of the most closely packed situation. Hence 

 causation of this rigid t3^e really became unintelligible. 

 Not even the old fiction of an ether which embraced all 

 material things, and as a vehicle made transmission of influ- 

 ence from one to the other possible, seemed able to overcome 

 the contradictions into which thought had landed itself 

 through its hard and narrow concepts of cause and effect. 

 And in fact there is no way out of the impasse but by retrac- 

 ing our steps and recognising that these concepts are partial 

 and misleading abstractions. We have to return to the fluid- 

 ity and plasticity of nature and experience in order to find 

 the concepts of reality. When we do this we find that round 

 every luminous point in experience there is a gradual shading 

 off into haziness and obscurity. A " concept " is not merely 

 its clear luminous centre, but embraces a surrounding sphere 

 of meaning or influence of smaller or larger dimensions, in 

 which the luminosity tails off and grows fainter until it dis- 

 appears. Similarly a " thing " is not merely that which pre- j 

 sents itself as such in clearest definite outline, but this central \ 

 area is surrounded by a zone of intuitions and influences j 

 which shades off into the region of the indefinite. The hard ' 

 abrupt contours of our ordinary conceptional system do not 

 apply to reality and make reality inexplicable, not only in 

 the case of causation, but in all cases of relations between 

 things, qualities, and ideas. Conceive of a cause as a centre 



