Adding more people causes problems. But people are also the means to solve these problems. The main fuel to speed the world’s progress is our stock of knowledge; the brakes are our lack of imagination and unsound social regulations of these activities. The ultimate resource is people—especially skilled, spirited, and hopeful young people endowed with liberty—who will exert their wills and imaginations for their own benefits, and so inevitably they will benefit the rest of us as well.

The increase in the world's population represents our victory over death.

Progress toward a more abundant material life does not come like manna from heaven. . . . My message certainly is not one of complacency. In this I agree with the doomsayers: our world needs the best efforts of all humanity to improve our lot.

People call me an optimist, but I'm really an appreciator ... years ago, I was cured of a badly infected finger with antibiotics when once my doctor could have recommended only a hot water soak or, eventually, surgery.... When I was six years old and had scarlet fever, the first of the miracle drugs, sulfanilamide, saved my life. I'm grateful for computers and photocopiers ... I appreciate where we've come from.

All of us necessarily hold many casual opinions that are ludicrously wrong simply because life is far too short for us to think through even a small fraction of the topics that we come across.

The main fuel to speed the world's progress is our stock of knowledge, and the brake is our lack of imagination.

The world's problem is not too many people, but lack of political and economic freedom.