We had a shared experience. That makes a good marriage better. In many ways our marriage is great because she has made it great.

We are a caring nation, and our values should also guide us on how we harness the gifts of science. New medical breakthroughs bring the hope of cures for terrible diseases and treatments that can improve the lives of millions. Our challenge is to make sure that science serves the cause of humanity instead of the other way around.

Liberty can change habits.

These demands are not open to negotiation or discussion.

I really think it's important for presidents to exit the stage gracefully.

So, for example, a country was into recession right after I was sworn in, a dot-com bust had taken place. Then the attacks of September the 11th, and then of course the great financial meltdown in the - the fundamental question facing any presidency is how do you deal with the hand you’re dealt?

I remember, right after Hezbollah launched its rocket attacks on Israel, I said: This is a clarifying moment; this is a chance for the world to see the threats of the 21st century, the challenge we face.