let us say, then, that instinct and intelligence imply two radically different kinds of knowledge. it has been asked how far instinct is conscious... instinct is more or less conscious in certain cases, unconscious in others... but here we must point out a difference, not often noticed, between two kinds of unconsciousness, that in which consciousness is absent, and that in which consciousness is nullified.  
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 performance 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 stopper. this inadequacy of act to representation is precisely what we here call consciousness.
if we examine this point more closely, we shall find that consciousness is the light that plays around the zone of possible actions or potential activity which surrounds the action really performed by the living being. it signifies hesitation or choice. where many equally possible actions are indicated without there being any real action (as in a deliberation that has not come to an end), consciousness is intense. where the action performed is the only action possible (as in activity of the somnambulistic or more generally automatic kind), consciousness is reduced to nothing. 

henri bergson's creative evolution,
intelligence and instinct.