Kill one man, and you are a murderer. Kill millions of men, and you are a conqueror. Kill them all, and you are a god.

Renown? I've already got more of it than those I respect, and will never have as much as those for whom I feel contempt.

Beauty in art is often nothing but ugliness subdued.

What scientist would not long to go on living, if only to see how the little truths he has brought to light will grow up?

The biologist passes. The frog stays the same.

A body of work such as Pasteur's is inconceivable in our time: no man would be given a chance to create a whole science. Nowadays a path is scarcely opened up when the crowd begins to pour in.

It is sometimes well for a blatant error to draw attention to overmodest truths.