A book which, above all others in the world, should be forbidden, is a catalogue of forbidden books.

To read means to borrow; to create out of one s readings is paying off one's debts.

The natural scientists of the previous age knew less than we do and believed they were very close to the goal: we have taken very great steps in its direction and now discover we are still very far away from it. With the most rational philosophers an increase in their knowledge is always attended by an increased conviction of their ignorance.

Those who never have time do least

We are obliged to regard many of our original minds as crazy at least until we have become as clever as they are.

There is a great difference between believing in something and believing in it again.

People who never have any time on their hands are those who do the least.