I don't have the illusion that there's any position or role in the world with as much potential for bringing about change as that of president of the United States.

...the emergent capabilities bursting forth from the revolutionary advances in the life sciences are about to make us the principal agent of evolution.

The message from Wal-Mart today to the rest of the business community is there need not be any conflict between the environment and the economy. We will find the way not only to reconcile (those), but to find new profits and new opportunities as we do the right thing.

If we walk down the sidewalk of any street in America a significant number of the people we pass by, if we dug into what they're going through in their lives, they're carrying burdens that they don't talk about but they're extremely heavy and painful. And so, one of the secrets of the human condition is that suffering binds people together. And when you go through something agonizing, others who know what you're feeling because they've been through it will so often reach out to you and connect with you, and give you strength and lift you up.

I have faith in the United States and our ability to make good decisions based on the facts.

I'm naturally an optimist, but my basis for hope is rooted in my understanding of human nature.

The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore.