Speed is what distinguishes intelligence. No bird discovers how to fly: evolution used a trillion bird-years to 'discover' that – where merely hundre… - Marvin Minsky

The way the mathematics game is played, most variations lie outside the rules, while music can insist on perfect canon or tolerate a casual accompaniment.

Since we have no systematic way to avoid all the inconsistencies of commonsense logic, each person must find his own way by building a private collection of "cognitive censors" to suppress the kinds of mistakes he has discovered in the past.

I am inclined to doubt that anything very resembling formal logic could be a good model for human reasoning. In particular, I doubt that any logic that prohibits self-reference can be adequate for psychology: no mind can have enough power — without the power to think about Thinking itself. Without Self-Reference it would seem immeasurably harder to achieve Self-Consciousness — which, so far as I can see, requires at least some capacity to reflect on what it does. If Russell shattered our hopes for making a completely reliable version of commonsense reasoning, still we can try to find the islands of "local consistency," in which naive reasoning remains correct.