Trust not the heart of that man for whom old clothes are not venerable.

Perfect ignorance is quiet, perfect knowledge is quiet; not so the transition from the former to the latter.

Silence is the eternal duty of man.

Do not be embarrassed by your mistakes. Nothing can teach us better than our understanding of them. This is one of the best ways of self-education.

The graceful minuet-dance of fancy must give place to the toilsome, thorny pilgrimage of understanding. On the transition from the age of romance to that of science.

The person who cannot laugh is not only ready for treason, and deceptions, their whole life is already a treason and deception.

He that has done nothing has known nothing.