It helps me sleep at night.

Fool me once, shame on - shame on you. Fool me - you can't get fooled again.

Leadership to me means duty, honor, country. It means character, and it means listening from time to time.

Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America. These acts shatter steel, but they cannot dent the steel of American resolve.

Freedom itself was attacked this morning by a faceless coward, and freedom will be defended.

Our enemies are innovative and resourceful, and so are we. They never stop thinking about new ways to harm our country and our people, and neither do we.

Freedom is not our gift to the world it is God's gift to humanity.

To those of you who received honours, awards and distinctions, I say, well done. And to the C students, I say, you too can be president of the United States.

I do solemnly swear that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States

A dictatorship would be a heck of a lot easier, there's no question about it.

I believe a marriage is between a man and a woman.

The minimum you should do with your life is to at least reproduce it.

Expect little, and we live up to the expectation. Expect a lot, and we stretch and grow to meet the expectation.

For in my nature I quested for beauty, but God, God hath sent me to sea for pearls.

I go out there. I'm out there every day. [Pause] There is nothing out there.

I enjoy competing in the marketplace of free ideas.

The less you know about a field, the better your odds. Dumb boldness is the best way to approach a new challenge.

I listen to the Beatles all the time - in my car, at the gym. The Beatles are still part of my life. And because of that, John Lennon - in life and in death - remains part of my life.

I think the climate is too important to say we are going to wait until all our economic woes are over before we act effectively.

You can go into all sorts of situations with a camera and people will think they should serve it.

I always tried to work hard and stay focused, and just use one opportunity to contribute to the next.