The next most dangerous thing [after nuclear proliferation] is probably... global warming, and then, right behind that are overpopulation -- we need to get serious about family planning-and trying to alleviate poverty, to get clean, renewable energy, probably with solar panels to the billion and a half people in the world who don't have access to electricity.

Every action or inaction has an impact-good or bad-upon our surroundings, and anything we do today will have an impact on the lives of our grandchildren.

Do something. Either lead, follow or get out of the way.

If you never quit, you're never beaten.

I don't measure success in numbers, but I consider my contributions of more than $1.3 billion to various causes over the years to be one of my proudest accomplishments and the best investment I've ever made. Those dollars have improved lives, saved species, fought disease, educated children, inspired change, challenged ideas and opened minds; at the time of my death, virtually all of my wealth will have gone to charity.

We won't be signing off until the world ends. We'll be on, and we will cover the end of the world, live, and that will be our last event . . . we'll play 'Nearer, My God, to Thee' before we sign off.

The Iranians don't intimidate! They're like the Vietnamese and the Iraqis. You want to start a war with them? They'll still be fighting in fifty years!