If we ever do find a better system, I'll be happy to call myself an anti-capitalist.

I honestly don't know, but if America continues to refuse to reduce its greenhouse gas emissions, I see a bleak future not only for American society, but for the world as a whole. This is a global problem that is not going away, and the United States is an obstacle to solving it.

If you have the abilities to earn a lot of money and if you have the character to persist in giving that to the most effective charities you can find, then that may be the best thing that you can do. And - also, if you do become a Wall Street banker, I think you need to be aware of what you're doing in terms of your daily work, not just earning money to give a lot away. But you need to think about - am I harming people through the work that I'm doing?

So why don't we make ourselves the last generation on earth? If we would all agree to have ourselves sterilized then no sacrifices would be required - we could party our way into extinction!

At the descriptive level, certainly, you would expect different cultures to develop different sorts of ethics and obviously they have; that doesn't mean that you can't think of overarching ethical principles you would want people to follow in all kinds of places.

Sci-fi is often a metaphor. I think it's more the themes and questions that science fiction raises rather than the exact predictions that should guide us.

Killing a defective infant is not morally equivalent to killing a person. Sometimes it is not wrong at all.