Recommending or insisting on abstinence has been completely ineffective.

Everyone you will ever meet knows something you don't.

We are just a speck, on a speck, orbiting a speck, in the corner of a speck, in the middle of nowhere.

To leave the world better than you found it, sometimes you have to pick up other people's trash.

Science is the best idea humans have ever had. The more people who embrace that idea, the better.

You and I are made of stardust. We are the stuff of exploded stars. We are therefore, at least 1 way that the Universe knows itself. That, to me, is astonishing.

There's nothing I believe in more strongly than getting young people interested in science and engineering, for a better tomorrow, for all humankind.

I speak with dogs frequently. They don't really talk, but I feel they're communicating.

The natural world is a package deal; you don't get to select which facts you like and which you don't.

The more you find out about the world, the more opportunities there are to laugh at it.

Science is the best thing humans beings have ever come up with. And if it isn't, science will fix it.

Your fear of the truth does not hide or dilute it.

What is the mass of a feeling? What is its wavelength, its position on the electromagnetic spectrum?

Remorse shows the difference between a cruel person and one that is not.

There is always inequality in life. Some men are killed in a war and some men are wounded and some men never leave the country. Life is unfair.

Brothers and sisters of Egypt, you have given the world the most precious gift: the belief that ultimately right will prevail.

Time can't be managed. I merely manage activities. Each night, I write down on a sheet of paper a list of the things I have to accomplish the next day. And when I wake up ... I do them.

Whoever wants to understand much must play much.

I wanted to be a psychological engineer, but we lacked the facilities, so I did the next best thing - I went into politics. It's practically the same thing.

Postponing doing the really interesting things in life for later, when you don't have the energy.

Those who wish to appear wise among fools, among the wise seem foolish.