[T]hat is the triumph of history - truth absolute is not at hand; the original with which to match the copy does not exist.

Of true knowledge at any time, a good part is merely convenient, necessary indeed to the worker, but not to an understanding of his subject: One can judge a building without knowing where to buy the bricks; one can understand a violin sonata without knowing how to score for the instrument. The work may in fact be better understood without a knowledge of the details of its manufacture, of attention to these tends to distract from meaning and effect.

The intellectuals' chief cause of anguish are one another's works.

Idealism springs from deep feelings, but feelings are nothing without the formulated idea that keeps them whole.

I have always been - I think any student of history almost inevitably is - a cheerful pessimist.

Convince yourself that you are working in clay, not marble, on paper not eternal bronze: Let that first sentence be as stupid as it wishes.

Out of man's mind in free play comes the creation Science. It renews itself, like the generations, thanks to an activity which is the best game of homo ludens: science is in the strictest and best sense a glorious entertainment.