They're talking about things of which they don't have the slightest understanding, anyway. It's only because of their stupidity that they're able to be so sure of themselves.
From outside one will always triumphantly impress theories upon the world and then fall straight into the ditch one has dug, but only from inside will one keep oneself and the world quiet and true.
Every new discovery is assumed at once into the sum total of knowledge, and with that ceases in a sense to be a discovery; it dissolves into the whole and disappears, and one must have a trained scientific eye even to recognize it after that.
Man cannot live without a permanent trust in something indestructible in himself, though both the indestructible element and the trust may remain permanently hidden from him. One of the ways in which this hiddenness can express itself is through faith in a personal god.