Looking back on my career, I think I've been extremely fortunate to be in the right place at the right time in order to have the influence that I did.

Remember that not everyone is as strong as you are. Be mindful of human weakness, and of the fact that it may be more important, in the long run, to get many people taking steps in the right direction than to have fewer achieving the ideal.

In a situation where many national leaders do the same thing and look out for national interests, and with an issue like global warming, you're likely to get no solution, so I think you have to have some kind of ethical trump on some of those issues.

Charitable giving is a huge sector in the United States. It amounts to $350 billion a year. And yet, I can't help feeling that a lot of that is wasted because people have not been thinking about how to do it as effectively as possible.

We may feel the pain of falling back from a level of affluence to which we have grown accustomed, but most people in developed countries are still, by historical standards, extraordinarily well off.

People may hope that the meat they buy came from an animal who died without pain, but they do not really want to know about it. Yet those who, by their purchases, require animals to be killed do not deserve to be shielded from this or any other aspect of the production of the meat they buy.

Torturing a human being is almost always wrong, but it is not absolutely wrong.