And what is a man without energy? Nothing - nothing at all.

the size of a misfortune is not determinable by an outsider’s measurement of it but only by the measurements applied to it by the person specially affected by it.

When I am king they shall not have bread and shelter only, but also teachings out of books, for a full belly is little worth where the mind is starved.

When in doubt tell the truth.

There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.

A successful book is not made of what is in it, but what is left out of it.

Nothing exists but you. And you are but a thought.