Use words to please, to instruct, to soothe. Then stop speaking.

It is better to listen to a crow that lives in trees than to a learned man who lives only in ideas.

It is noble to pity a man who is cruel because he is weak, but it is idiotic and dangerous to allow him to have power.

I would live in a world of Christ-like humans, but not one full of Christians, may God forgive me.

Knowledge often spoils devotion.

The secret of change is to focus all of your energy, not on fighting the old, but on building the new.

I never go looking for a sucker. I look for a Champion and make a sucker of of him.

We don't go to school to learn, but to be soaked in the prejudices of our class, without which we should be useless and unhappy.

You have a row of dominoes set up; you knock over the first one, and what will happen to the last one is that it will go over very quickly.

You really, really have to care about animals to want to kill one. You have to learn all this stuff about them and start thinking like them.

We are here to repair the world. I grew up thinking that was what everybody was trying to do.

One of my motivations to become a blood specialist was to study malaria in red blood cells. But in science, you discover something and you want to go this way, but your work goes that way.

The mind that is anxious about future events is miserable.

There are five signs of righteousness: a gentle disposition and a soft heart, shedding tears of regret, ascetism and not caring about the world, being unambitious, and having a conscience.