A guilty conscience is the mother of invention.

A blunder at the right moment is better than cleverness at the wrong time.

Advice is one of those things it is far more blessed to give than to receive.

A cynic is a man who looks at the world with a monocle in his mind's eye.

It is the interest one takes in books that makes a library. And if a library have interest it is; if not, it isn't.

Of two evils choose the prettier.

Youth is a silly, vapid state, Old age with fears and ills is rife; This simple boon I beg of Fate - A thousand years of Middle Life.

I am more fond of achieving than striving. My theories must prove to be facts or be discarded as worthless. My efforts must soon be crowned with success, or discontinued.