The idea that we can actually have an impact on places more or less instantly, too, by responding in some way or not responding, I think, also makes it true.

In the past 20 years alone, it adds up to more death than were caused by all the civil and international wars adn government repression of the entire twentieth century, the century of Hitler and Stalin. How much would we give to prevent those horrors? Yet how little are we doing to prevent today's even larger toll and all the misery that it involves? I believe that if you read this book to the end, and look honestly and carefully at our situation, assessing both the facts and the ethical arguments, you will agree that we must act.

The Internet, like the steam engine, is a technological breakthrough that changed the world.

When children see animals in a circus, they learn that animals exist for our amusement. Quite apart from the cruelty involved in training and confining these animals, the whole idea that we should enjoy the humiliating spectacle of an elephant or lion made to perform circus tricks shows a lack of respect for the animals as individuals.

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.

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.

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.