Ethics is prescriptive and can change behavior, but usually only at the margins.

If you're interested in doing something about climate change as we all should be, all of us who care about future people and creatures that will inhabit this world. Then buying a Prius is a good thing but an even better thing would be to be on the streets demanding urgent action from the United States' Congress.

Aristotle thought that humans are rational animals and Hobbes thought that we act on the basis of rational self-interest. If only! It's not that we never do these things, it's that they are hardly constituative of who and what we are.

Much of the point of individual action is really to communicate with other people and with political leaders and to demonstrate to them that we are willing to live lives which are less dependent on fossil fuels and we'll show you that now by changing our individual life to some extent but we want you to take action, political leaders, so that we aren't living in a society in which we're dependent on poisoning the future in order to maintain present lifestyles.

The only way major change in environmental policy is going to happen, the only way, is if there is a very strong, very active popular movement that demands it and such a movement would be unparalleled because it would be a popular movement that says, "Raise our taxes so that we change our behavior."

On my reading of history people who want to bring us the best are usually the people we ought to be afraid of.

None of us are rational economic men as we're supposed to be portrayed in economic theory where mixes of passions, of desires, of moral principles, of self-deception, of altruism, of concern of others, of concerns for ourselves and an interest in our bank accounts. And social policies have to be responsive to the complexity of who we are as people or else, like the war on drugs, they're simply going to fail.