On certain occasions, the eyes of the mind can supply the want of the most powerful telescopes, and lead to astronomical discoveries of the highest importance.

To get to know, to discover, to publish-this is the destiny of a scientist.

Where should be be if we set ourselves to deny everything we do not know how to explain?

Euler calculated without effort, just as men breathe, as eagles sustain themselves in the air.

Let us award a just, a brilliant homage to those rare men whom nature has endowed with the precious privilege of arranging a thousand isolated facts, of making seductive theories spring from them; but let us not forget to state, that the scythe of the reaper had cut the stalks before one had thought of uniting them into sheaves!

I was often humiliated to see men disputing for a piece of bread, just as animals might have done. My feelings on this subject have very much altered since I have been personally exposed to the tortures of hunger. I have discovered, in fact, that a man, whatever may have been his origin, his education, and his habits, is governed, under certain circumstances, much more by his stomach than by his intelligence and his heart.

In the experimental sciences, the epochs of the most brilliant progress are almost always separated by long intervals of almost absolute repose.