You're only as young as the last time you changed your mind.

The ability to learn is the most important quality a leader can have.

Human beings must always be on the watch for the coming of wonders.

It's more difficult to be simple, and it's easier to be more complicated.

I'm doing many different things to prepare for the inevitable failure of one of them.

Trifles make perfection, and perfection is no trifle.

I would rather walk with a friend in the dark than walk alone in the light.

We are all of us obliged... to nurse a few little follies in ourselves.

What you think about day and night forms your character and personality.

The truth is the light and light is the truth.

Learning never exhausts the mind.

Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.