Climate change involves fundamental choices about how we want to live and what kind of world we want.

Moral revolutions are typically seen retrospectively. Prospectively, the revolutionaries tend to look like crazy people, and sometimes they are.

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.

The millennium development goals are important, both morally and economically, because much of the world's population maybe is as much as a third of the world's population hasn't yet reached the level of economic development where we begin to get a dissociation from people's economic status and their reports about personal happiness. So we really do need to do much more and much more effectively in order to give everyone the kind of basis for which they can have good vibes.

I begin with human psychology and then see what we can say about ethics.

We need more science, but what we especially need is science fiction.

Many environmental questions are in a deep way philosophical, despite our penchant for treating them as if they were only technological, economic, or whatever.