Ask yourself whether our language is complete--whether it was so before the symbolism of chemistry and the notation of the infinitesimal calculus were incorporated in it; for these are, so to speak, suburbs of our language. (And how many houses or streets does it take before a town begins to be a town?) Our language can be seen as an ancient city: a maze of little streets and squares, of old and new houses, and of houses with additions from various periods; and this surrounded by a multitude of new boroughs with straight regular streets and uniform houses.

You can't think decently if you're not willing to hurt yourself

Genius is talent exercised with courage.

I won't say 'See you tomorrow' because that would be like predicting the future, and I'm pretty sure I can't do that.

The subject does not belong to the world; rather, it is a limit of the world.

Resting on your laurels is as dangerous as resting when you are walking in the snow. You doze off and die in your sleep.

Suppose someone follows the series "1,3,5,7, ..", and in writing the series 2x+1; and he asked himself "But am I always doing the same thing, or something different every time?" If from one day to the next someone promises: "Tomorrow I will give up smoking", does he say the same thing every day, or every day something different?