I made it clear to the Congress that I will not allow our nation to cross this moral line. I felt like crossing this line would be a mistake, and once crossed, we would find it almost impossible to turn back. Crossing the line would needlessly encourage a conflict between science and ethics that can only do damage to both, and to our nation as a whole. If we're to find the right ways to advance ethical medical research, we must also be willing, when necessary, to reject the wrong ways. So today, I'm keeping the promise I made to the American people by returning this bill to Congress with my veto.