There is nothing in this world constant, but inconstancy.

God, give us the grace to accept with serenity the things that cannot be changed, courage to change the things which should be changed, and the wisdom to distinguish the one from the other.

The ones who are crazy enough to think they can change the world are the ones that do.

I have to face life with a newly found passion. I must rediscover the irresistible will to learn, to live and to love.

They [the Americans] have all a lively faith in the perfectibility of man, they judge that the diffusion of knowledge must necessarily be advantageous, and the consequences of ignorance fatal; they all consider society as a body in a state of improvement, humanity as a changing scene, in which nothing is, or ought to be, permanent; and they admit that what appears to them today to be good, may be superseded by something better tomorrow.

Maturity is the ability to live in peace with that which we cannot change.

It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.

He who would learn to fly one day must first learn to stand and walk and run and climb and dance; one cannot fly into flying.

Long-term consistency trumps short-term intensity.

The art of war is simple enough. Find out where your enemy is. Get at him as soon as you can. Strike at him as hard as you can and as often as you can, and keep moving on.