In the last few centuries we've managed to reduce how much we kill each other, we've learned some basic lessons about public health, and life is relatively good for more people than ever before.

Well, one measure of a good life, I think, is to be engaged in projects that one thinks are meaningful and worthwhile. So I would put the emphasis of a good life on activity, on the walk rather than the destination, and I think that most of the things that any of us do that are really valuable and really important are projects that we really shouldn't expect to be completed in our lifetime because if they could completed in our lifetime, they probably wouldn't be so important that we should devote our lives to them.

Ethical systems are fundamentally conservative and primarily directed towards regulating interactions within communities.

Climate scientists think of nothing but climate and then express their concerns in terms of constructs such as global mean surface temperature. But we live in a world in which all sorts of change is happening all the time, and the only way to understand what climate change will bring is to tell stories about how it manifests in people's lives.

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.

It's true that climate change is an unprecedented problem so it's not surprising that it's so difficult to address.

Our traditional systems of decision-making are just not up to preventing changes in fundamental earth systems that are driven by a constant barrage of individually negligible emissions of an invisible, odorless gas, by billions of people all over the world.