Peter Singer

In a situation where many national leaders do the same thing and look out for national interests, and with an issue like global warming, you're likely to get no solution, so I think you have to have some kind of ethical trump on some of those issues.

I'm not overly alarmist about it, but I do think there are some worrying signs, like the growing accumulation of wealth by a very small proportion of the population, plus elections in the US are much more dominated by money than anywhere else calling itself a democracy.

We need to learn how to capture and kill wild fish humanely - or, if that is not possible, to find less cruel and more sustainable alternatives to eating them.

I suppose what's happened recently has confirmed suspicions I voiced in the book, and I think made clearer some of those things that I point out. For instance I have a section of the book where I talk about the possibility of torture.

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.

If you go back in time you'll find tribes that were essentially only concerned with their own tribal members. If you were a member of another tribe, you could be killed with impunity.