"Whilst [intelligence] is inferior to the natural instrument for the satisfaction of immediate wants, its advantage over it is greater, the less urgent the need. Above all, it reacts on the nature of the being that constructs it; for in calling on him to exercise a new function, it confers on him, so to speak, a richer organization, being an artificial organ by which the natural organism is extended. For every need that it satisfies, it creates a new need; and so, instead of closing, like instinct, the round of action within which the animal tends to move automatically, it lays open to activity an unlimited field into which it is driven further and further, and made more and more free." --Henri Bergson, qtd. in Jussi Parrika's Insect Media.
I'm a little leery of an intelligence/instinct duality, but there's something about the notion that tools open where instinct closes that appeals to me.