We reject the use of national security letters to spy on citizens who are not suspected of a crime.

You can’t let your failures define you. You have to let your failures teach you.

Change will not come if we wait for some other person or some other time. We are the ones we've been waiting for. We are the change that we seek.

Keep exploring. Keep dreaming. Keep asking why. Don’t settle for what you already know. Never stop believing in the power of your ideas, your imagination, your hard work to change the world.

When ignorant folks want to advertise their ignorance, you don't really have to do anything, you just let them talk.

Just because we have the best hammer does not mean that every problem is a nail.

Change is never easy, but always possible.

Don’t ever let anybody tell you that your efforts don’t matter or that your voice doesn’t count. Don’t ever believe that you can’t make a difference. You have.

Where you are right now doesn't have to determine where you'll end up.

Learning to stand in somebody else's shoes, to see through their eyes, that's how peace begins. And it's up to you to make that happen. Empathy is a quality of character that can change the world.

If somebody is different from you, that's not something you criticize, that's something that you appreciate.

I was hated, you know. I made no secret of the fact that I was an atheist. People told me there are no atheists in fox holes. That's nonsense. [interview promoting Marching as to War (2002)]

Be available for life to happen.

You know, the reward for 'Captain America' is amazing. It's always fun to see a giant spectacle film and see the fun stuff - the special effects.

I think it must be apparent to every thinking mind that the noblest of all professions is that of teaching, and that upon the effectiveness of that teaching hangs the destiny of nations.

He who knows, knows not. He who knows not, knows.

If one takes care of the means, the end will take care of itself.

The quantum hypothesis will eventually find its exact expression in certain equations which will be a more exact formulation of the law of causality.

If we dont heal our own hood, who will?

President Eisenhower was a fine general and a good, decent man, but if he had fought World War II the way he fought for civil rights, we would all be speaking German now.

A great step towards independence is a good-humored stomach, one that is willing to endure rough treatment.