He who hasn't tasted bitter things hasn't earned sweet things.

Virtue is the habit of acting according to wisdom.

Nature does not make leaps.

It is unworthy of excellent men to lose hours like slaves in the labor of calculation which could be relegated to anyone else if machines were used.

Indeed in general I hold that there is nothing truer than happiness, and nothing happier and sweeter than truth.

The words 'Here you can find perfect peace' can be written only over the gates of a cemetery.

Imaginary numbers are a fine and wonderful refuge of the divine spirit almost an amphibian between being and non-being.