ii INTELLIGENCE AND INSTINCT 151 



some explanations are first of all necessary on the 

 subject of consciousness in general. 



It has been asked how far instinct is conscious. 

 Our reply is that there are a vast number of differences 

 and degrees, that instinct is more or less conscious in 

 certain cases, unconscious in others. The plant, as we 

 shall see, has instincts ; it is not likely that these are 

 accompanied by feeling. Even in the animal there is 

 hardly any complex instinct that is not unconscious in 

 some part at least of its exercise. But here we must 

 point out a difference, not often noticed, between two 

 kinds of unconsciousness, viz., that in which conscious 

 ness is absent : , and that in which consciousness is nullified. 

 Both are equal to zero, but in one case the zero expresses 

 the fact that there is nothing, in the other that we 

 have two equal quantities of opposite sign which com 

 pensate and neutralize each other. The unconsciousness 

 of a falling stone is of the former kind : the stone 

 has no feeling of its fall. Is it the same with the 

 unconsciousness of instinct, in the extreme cases in 

 which instinct is unconscious ? When we mechanically 

 perform an habitual action, when the somnambulist 

 automatically acts his dream, unconsciousness may be 

 absolute ; but this is merely due to the fact that the 

 representation of the act is held in check by the per 

 formance of the act itself, which resembles the idea so 

 perfectly, and fits it so exactly, that consciousness is 

 unable to find room between them. Representation is 

 stopped up by action. The proof of this is, that if the 

 accomplishment of the act is arrested or thwarted by an 

 obstacle, consciousness may reappear. It was there, 

 but neutralized by the action which fulfilled and 

 thereby filled the representation. The obstacle creates 

 nothing positive ; it simply makes a void, removes a 



