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

A time will come when the science of destruction shall bend before the arts of peace; when the genius which multiplies our powers, which creates new products, which diffuses comfort and happiness among the great mass of the people, shall occupy in the general estimation of mankind that rank which reason and common sense now assign to it.

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!

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.

Such is the privilege of genius; it perceives, it seizes relations where vulgar eyes see only isolated facts.

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

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