The future of the world depends on how well we meet it.

Dolphins are social mammals, capable of enjoying their lives. They form close bonds with other members of their group.

Grain that is used to feed animals that end up on our tables as turkeys and hams could have gone to feed starving people.

I would like us to think about it more explicitly, and not take our intuitions as the given of ethics, but rather to reflect on it, and be more open about the fact that something is an ethical issues and think what we ought to do about it.

I know of a number of people who are successfully earning to give. That isn't for everyone but for those with the ability to earn a lot of money and the character to resist the temptation to spend it on themselves, it can be a great way to do good.

Take for example providing a guide dog for a blind person. That's a good thing to do, right? All right. It is a good thing to do. But you have to think what else you could do with the resources. It costs about $40,000 to train a guide dog and train the recipient so that the guide dog can be an effective help to a blind person. It costs somewhere between 20 and $50 to cure a blind person in a developing country if they have trachoma. So you do the sums, and you could provide one guide dog for one blind American or you could cure between 400 and 2,000 people of blindness.

In the sense that you're not at the centre of power, like a president or prime minister of a major power, everyone is marginalised; my position doesn't isn't unique in that respect. I think there are different sorts of relevance in different contexts.