"Many scientists who study artificial intelligence use the mathematics of formal logics--the predicate calculus--as their major tool to simulate thought.
But human thought--and its close relatives, problem solving and planning--seem more rooted in past experience than in logical deduction. Mental life is not neat and orderly. It does not proceed smoothly and gracefully in neat, logical form. Instead it hops, skips and jumps its way from idea to idea, tying together things that have no business being put together; forming new creative leaps, new insights and concepts. Human thought is not like logic; it is fundamentally different in kind and in spirit. The difference is neither worse nor better. But it is the difference that leads to creative discovery and to great robustness of behavior."
Donald A. Norman, The Design of Everyday Things, Basic Books, 1988. (p. 115 in 2002 paperback edition; highlights added for this post)