There is an obvious evolutionary explanation for the scarcity of altruistic saints: Without a strong predilection for their own interests, our ancestors would have been unlikely to survive, reproduce, and give their own offspring a chance of doing the same. Now conditions have changed and for most of us, surviving and reproducing isn't such a struggle but we still carry the genes of our ancestors and they influence - not determine, but influence - our behavior.

Human decision-making is complex. On our own, our tendency to yield to short-term temptations, and even to addictions, may be too strong for our rational, long-term planning.

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

History is not going to look kindly on us if we just keep our head in the sand on armed autonomous robotics issue because it sounds too science fiction.

My aim is to advocate that we make this mental switch in respect of our attitudes and practices towards a very large group of beings: members of species other than our own - or, as we popularly though misleadingly call them, animals. In other words, I am urging that we extend to other species the basic principle of equality that most of us recognize should be extended to all members of our own species.

I'm a Utilitarian, so I don't see the rule against lying as absolute; it's always subject to some overriding utility which may prevent its exercise.

Were we incapable of empathy – of putting ourselves in the position of others and seeing that their suffering is like our own – then ethical reasoning would lead nowhere. If emotion without reason is blind, then reason without emotion is impotent.