Philosophy is not a body of knowledge to impart to someone, that's why reading philosophy books isn't always the best way of learning philosophy. Philosophy is really more the process of rational engagement, rational reflection with a diversity of views and ideas and opinions and trying to sort of reason your way through to a more reflective position. I think if you look at it that way, philosophizing is to some extent some small way a part of almost everyone's lives although they don't recognize it as such and a lot of people are embarrassed about it.

I think the challenge of climate change in particular is the challenge for us to create and produce new norms for a new kind of world. And that's why I think as important as the issue of climate change is, it's even more important than it seems because if we can't evolve very quickly, new norms to deal with issues like climate change, we're not going to be able to survive in the kind of world we've created. So I think, really, the whole nature of democracy, of governance, of global community and of solving the kinds of problems of the 21st Century are really at stake.

The idea that we would raise billions of sentient animals, treat them horribly, pollute our waterways with their waste, compromise the effectiveness of our antibiotics so that they grow faster, and then slaughter them with little regard to their suffering so that we can feed off their corpses, will seem to most people unthinkably cruel and barbarous - sort of in the way that we think of medieval punishments, or Europeans today think of the death penalty.

I became religious and at 14 went to a boarding school 500 miles from home to begin theological studies. By the time I started university, politics had replaced religion in the economy of my enthusiasms but I had no idea what to study. My boarding school emphasized languages which I was bad at, and deemphasized math and science which I was good at.

We know the "great men" and a handful of heavily cited papers in our specialization. When there is a historical frame around a paper it's often a caricature that has become canonical.

People who go around saying that it is wrong to fly and to eat meat are not so much making appeals to us from within our shared morality, but engaging in something more like "persuasive definition." They want us to look at the world and ourselves in a different way. Someday these prohibitions against flying and eating meat may be written into our moral psychology, but it will only be after there are viable, widely shared alternatives that are beginning to be widely adopted.

I think the mother of all arguments against eating meat now is the climate change argument. Methane is a much more powerful greenhouse gas than carbon dioxide and when we eat meat we wipe away many of the good things that we do when we try to create greener and more sustainable practices in the rest of our lives. So if you add the concern for climate change with other concerns that were there. I think the case for vegetarianism is pretty overwhelming.