You know that I write slowly. This is chiefly because I am never satisfied until I have said as much as possible in a few words, and writing briefly takes far more time than writing at length.

I am coming more and more to the conviction that the necessity of our geometry cannot be demonstrated, at least neither by, nor for, the human intellect. . . G…

I mean the word proof not in the sense of the lawyers, who set two half proofs equal to a whole one, but in the sense of a mathematician, where half proof = 0,…

A great part of its theories derives an additional charm from the peculiarity that important propositions, with the impress of simplicity on them, are often ea…

Je n'ai fait celle-ci plus longue que parce que je n'ai pas eu le loisir de la faire plus courte.

Brevis esse laboro, obscurus fio.

I'm sorry this letter is so long, but I did not have time to make it shorter.