There is no self-knowledge except historical self-knowledge. No one knows what he is if he doesn't know what his contemporaries are.

Eternal life and the invisible world are only to be sought in God. Only within Him do all spirits dwell. He is an abyss of individuality, the only infinite plenitude.

There are three kinds of explanation in science: explanations which throw a light upon, or give a hint at a matter; explanations which do not explain anything; and explanations which obscure everything.

A good preface must be the root and the square of the book at the same time.

We should never invoke the spirit of antiquity as our authority. Spirits are peculiar things; they cannot be grasped with the hands and be held up before others. Spirits reveal themselves only to spirits. The most direct and concise method would be, in this case as well, to prove the possession of the only redeeming faith by good works.

Duty is for Kant the One and All. Out of the duty of gratitude, he claims, one has to defend and esteem the ancients; and only out of duty has he become a great man.

Publication is to thinking as childbirth is to the first kiss.