In science, if the last 50 years were the age of physics, the next 50 years will be the age of biology.

We know there are billions of stars and planets literally out there, and the universe is getting bigger. We know from our fancy telescopes that just in the last two years more than 20 planets have been identified outside our solar system that seem to be far enough away from their suns - - and dense enough - - that they might be able to support some form of life. So it makes it increasing less likely that we're alone. But if we were visited someday, I wouldn't be surprised.

You know, everybody makes mistakes when they are president.

Just as war is freedom's cost, disagreement is freedom's privilege.

What if [Saddam] fails to comply and we fail to act, or we take some ambiguous third route, which gives him yet more opportunities to develop this program of weapons of mass destruction? ... Well, he will conclude that the international community has lost its will. He will then conclude that he can go right on and do more to rebuild an arsenal of devastating destruction. And some day, some way, I guarantee you he'll use the arsenal.

And I have a plan to do even better, to end welfare as we know it

When some Republican governors asked to try new ways to put people on welfare back to work, the Obama Administration said they would only do it if they had a credible plan to increase employment by 20%. You hear that? More work. So the claim that President Obama weakened welfare reform's work requirement is just not true.