THE ASSOCIATION OF IDEAS 39 



case of retinal stimulation, A' is the process in the cone-cell, and 

 A is the color actually "seen." A is properly called the sensa- 

 tion in one of the several meanings of that term; namely, that 

 which we are conscious of or perceive through the mediation of a 

 sense organ. M, N, 0, etc., therefore, are other sense qualities, 

 or sensations, the consciousness of which is conditioned by the 

 arcs M'-m, N'-^n, O'-o, etc. The final, more complex, reaction 

 from A' to a and also to m, n, o, etc., conditions therefore the per- 

 ception of A, together with its associates, M, N, 0, etc. In con- 

 crete illustrative terms: the visual presentation of an apple no 

 longer arouses visual perception merely, but arouses also the per- 

 ception of the gustatory, olfactory, tactual, and possibly the 

 thermal qualities of the apple. 



It might be urged that in considering the reaction as the condi- 

 tion of consciousness we have put the emphasis in an almost ex- 

 clusive way on the efferent side; that it seems to make no differ- 

 ence where the reaction originates, so long as its terminations 

 are of a certain sort. This is not an accurate deduction. The 

 consciousness conditioned by the reaction, from A' to a, m, n, o, 

 etc., is not the same as that conditioned by the simultaneous re- 

 actions A'-a, M'-m, N'-n, O'-o, etc. In concrete terms: the 

 perception of the apple presented to the eye alone is not the same 

 as the perception of the apple which is sensibly seen, tasted, 

 smelled and felt at once or in quick succession. Perception, in 

 other words, is not mere multiple sensory intuition, and we shall 

 show later that it is not, on the other hand, mere sensory intuition 

 plus imagination, even in an analytical interpretation. 



Passing on to the topic of present chief interest : what is the con- 

 tent of thought? Again we have a deduction from our funda- 

 mental hypothesis which is amply verified by observation. There 

 are two contents for every state of thought-consciousness. First, 

 the muscular contraction which is responsible for the initiation 

 of the homeodetic reaction not the muscular contraction con- 

 sidered as a concrete whole, but that aspect of it which we call 

 the muscle sensation. The contraction as a whole is visible and 

 tangible, as well as sensible through the mediation of the muscle 

 spindle. When we speak of contraction we intend the total of 



