Everything excellent is as difficult as it is rare.

One who gains strength by overcoming obstacles possesses the only strength which can overcome adversity.

Medicine heals diseases of the body, wisdom frees the soul from passions.

Time wounds all heels.

All great achievements require time.

No act of kindness, no matter how small, is ever wasted.

If you don't want to slip up tomorrow, speak the truth today.

The boundaries which divide Life from Death are at best shadowy and vague. Who shall say where the one ends, and where the other begins?

Man's sensitivity to the little things and insensitivity to the greatest are the signs of a strange disorder.

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self.

Adapt what is useful, reject what is useless, and add what is specifically your own.

One new feature or fresh take can change everything.

Be frank and explicit. That is the right line to take when you wish to conceal your own mind and to confuse the minds of others.

Half the world is composed of people who have something to say and can't, and the other half who have nothing to say and keep on saying it.

Great dreams of great dreamers are always transcended.

Wisdom begins at the end.

By three methods we may learn wisdom: first, by reflection which is noblest; second, by imitation, which is the easiest; and third, by experience, which is the bitterest.

Learn from the mistakes of others. You can never live long enough to make them all yourself.

Obsession is the wellspring of genius and madness.

Don't criticize what you don't understand, son. You never walked in that man's shoes.

Simplicity is the ultimate sophistication.