When he to whom one speaks does not understand, and he who speaks himself does not understand, that is metaphysics.

When he to whom a person speaks does not understand, and he who speaks does not understand himself, that is metaphysics.

He who knows, does not speak. He who speaks, does not know.

He who does not understand a joke, he does not understand Danish.

When he that speaks, and he to whom he speaks, neither of them understand what is meant, that is metaphysics

Four thousand volumes of metaphysics will not teach us what the soul is