Experience is, in fever and anguish, the putting into question (to the test) of that which a man knows of being. Should he in this fever have any apprehension whatsoever, he cannot say: I have seen God, the absolute, or the depths of the universe ; he can only say that which I have seen eludes understanding —and God, the absolute, the depths of the universe are nothing if they are not categories of the understanding.

If I said decisively, I have seen God, that which I see would change. Instead of the inconceivable unknown—wildly free before me, leaving me wild and free before it—there would be a dead object and the thing of the theologian, to which the unknown would be subjugated.

p. 4 - L'Expérience Intérieure (1943)