Philosophy is the history of philosophy.

The heart-throb for the welfare of humanity therefore passes into the ravings of an insane self-conceit, into the fury of consciousness to preserve itself from destruction; and it does this by expelling from itself the perversion which it is itself, and by striving to look on it and express it as something else.

...if the fear of falling into error is the source of a mistrust in Science, which in the absence of any such misgivings gets on with the work itself and actually does know, it is difficult to see why, conversely, a mistrust should not be placed in this mistrust, and why we should not be concerned that this fear of erring is itself the very error.

Every idea, extended into infinity, becomes its own opposite.

The courage of the truth is the first condition of philosophic study.

We learn from history that man can never learn anything from history.

Truth in philosophy means that concept and external reality correspond.