Common sense

...My thesis now is this, that our fundamental ways of thinking about things are discoveries of exceedingly remote ancestors, which have been able to preserve themselves throughout the experience of all subsequent time. They form one great stage of equilibrium in the human mind's development, the stage of common sense. Other stages have grafted themselves upon this stage, but have never succeeded in displacing it. Let us consider this common-sense stage first, as if it might be final.

In practical talk, a man's common sense means his good judgment, his freedom from excentricity, his gumption, to use the vernacular word. In philosophy it means something entirely different, it means his use of certain intellectual forms or categories of thought. Were we lobsters, or bees, it might be that our organization would have led to our using quite different modes from these of apprehending our experiences. It might be too (we cannot dogmatically deny this) that such categories, unimaginable by us to-day, would have proved on the whole as serviceable for handling our experiences mentally as those which we actually use...
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There is no ringing conclusion possible when we compare these types of thinking, with a view to telling which is the more absolutely true. Their naturalness, their intellectual economy, their fruitfulness for practice, all start up as distinct tests of their veracity, and as a result we get confused. Common sense is better for one sphere of life, science for another, philosophic criticism for a third; but whether either be truer absolutely, Heaven only knows...

Pragmatism, Lecture 5