The problem is that for almost any feature of humanity that you can name, whether it's the ability to suffer, whether it's the capacity to reason, whether it's having lives that can go better or worse, there are at least some other non-human animals that have all of these features as well. So to exclude non-human animals from the range of moral concern but to include all humans, just seems morally arbitrary.

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

Our differences should not be exaggerated.

The problem is that for almost any feature of humanity that you can name, whether it's the ability to suffer, whether it's the capacity to reason, whether it's having lives that can go better or worse, there are at least some other non-human animals that have all of these features as well. So to exclude non-human animals from the range of moral concern but to include all humans, just seems morally arbitrary.

Moral revolutions are typically seen retrospectively. Prospectively, the revolutionaries tend to look like crazy people, and sometimes they are.

The Consequentialist trinity is typically regarded in this way: Bentham is crude, Mill's writings are full of howlers and inconsistencies, and Sidgwick was too smart to fully embrace Consequentialism. All of these great traditions in moral philosophy express strands of our moral consciousness and they should all be treated as research programs rather than as fully determinate views that can be leveled by a counterexample or by a clever argument.

I think when it comes to climate change, the single most important thing in the world is for the United States' Congress to pass an effective bill that will put a price in carbon because if it starts costing something to emit carbon, this will provide an incentive, people do act on the basis to some extent of economic incentives to emit fewer greenhouse gases.