What is meant by computation? When I wrote that intelligence is not computation, I must have meant a certain sort of computation because of course all thought is some kind of computation.

Gah, Thank You. Saves me the trouble of a long reply. I'll upvote for a change-of-mind disclaimer in the original.

Intelligent thinking seems to really be guesses followed by verification, not steady linear deduction.

My recent thoughts have been along these lines, but this is also what evolution does. At some point, the general things learned by guessing have to be incorporated into the guess-generating process.