Sickness is mankind's greatest defect.

There seems to be some perverse human characteristic that likes to make easy things difficult.

I despise people who depend on these things [heroin and cocaine]. If you really want a mind-altering experience, look at a tree.

All is in the hands of man. Therefore wash them often.

I can calculate the motion of heavenly bodies but not the madness of people.

Who makes us ignorant? We ourselves. We put our hands over our eyes and weep that it is dark.

A question that sometimes drives me hazy: Am I, or the others, crazy?

By providing students in our Nation with such an education, we help save our children from the clutches of poverty, crime, drugs, and hopelessness, and we help safeguard our Nation's prosperity for generations yet unborn.

Great men are like eagles, and build their nest on some lofty solitude.

No mortal can keep a secret. If the lips are silent, he chatters with his fingertips; betrayal oozes out of him at every pore.

If you talk to a man in a language he understands, that goes to his head. If you talk to him in his language, that goes to his heart.

Treat people as if they were what they ought to be, and you help them to become what they are capable of being.

A wise man can play the part of a clown, but a clown can't play the part of a wise man.

Not only will we have to repent for the sins of bad people; but we also will have to repent for the appalling silence of good people.

I like university professors, but you know, we shouldn't hold them up as the high-water mark of all human achievement. They're just a form of life, another form of life.

To live alone is the fate of all great souls.

The true measure of a man is how he treats someone who can do him absolutely no good.

In many people it is already an impertinence to say 'I'.

Example is not the main thing in influencing others. It is the only thing.

Our true nationality is mankind.

Every man takes the limits of his own field of vision for the limits of the world.