Doubt is not pleasant, but certainty is absurd, since we know nothing of first principles

There are some charlatans who admit no doubts. We know nothing of first principles. It is surely very presumptuous to define God, the angels, spirits, and to pretend to know precisely why God made the world, when we do not know why we can move our arms at our pleasure. Doubt is not a pleasant condition, but certainty is an absurd one.