One knows that the axioms are true not by inference of any kind, but by sense perception. When one perceives a tomato, for example, there is no evidence that it exists, beyond the fact that one perceives it; there is no evidence that it is something, beyond the fact that one perceives it; and there is no evidence that one is aware, beyond the fact that one is perceiving it. Axioms are perceptual self-evidences. There is nothing to be said in their behalf except: look at reality. What is true of tomatoes applies equally to oranges, buildings, people, music, and stars.