It would be nonsense to say that it was not in the interests of a stone to be kicked along the road...A stone has no interests because it cannot suffer. The capacity for suffering and enjoyment is, however, not only necessary, but also sufficient for us to say that a being has interests - at an absolute minimum, an interest in not suffering. A mouse, for example, does have an interest in not being kicked along the road because it will suffer if it is.

There are some circumstances, for example, where the newborn baby is severely disabled and where the parents think that it's better that child should not live, when killing the newborn baby is not at all wrong ... not like killing the chimpanzee would be.

Evolution has no moral direction. An evolutionary understanding of human nature can explain the differing intuitions we have when we are faced with an individual rather than with a mass of people, or with people close to us rather than with those far away, but it does not justify those feelings.

I would not question the sincerity of vegetarians who take little interest in Animal Liberation because they give priority to other causes; but when nonvegetarians say that "human problems come first" I cannot help wondering what exactly it is that they are doing for human beings that compels them to continue to support the wasteful, ruthless exploitation of farm animals.

If you're buying animal products and can go to the farm and actually see how the animals are looked after, yes, that's an important point. That's definitely the best way of assuring yourself that the animals are being well treated.

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.

I don't think there's much point in bemoaning the state of the world unless there's some way you can think of to improve it. Otherwise, don't bother writing a book; go and find a tropical island and lie in the sun.