I'd much rather be part of a society which greatly honors and respects people who are altruists and who are effective in their altruism, than one that either admires people because they're, you know, celebrity movie stars or because they're super wealthy just no matter what they do with their wealth because I think we ought to try to encourage more people to act in that way.

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.

For most humans, especially for those in modern urban and suburban communities, the most direct form of contact with nonhuman animals is at meal time: we eat them.... The use and abuse of animals raised for food far exceeds, in sheer numbers of animals affected, any other kind of mistreatment.

If possessing a higher degree of intelligence does not entitle one human to use another for his or her own ends, how can it entitle humans to exploit non-humans?

To be a utilitarian means that you judge actions as right or wrong in accordance with whether they have good consequences. So you try to do what will have the best consequences for all of those affected.

What is there about the notion of a person, at law, that makes every living member of the species Homo sapiens a person, irrespective of their mental capacities, but excludes every nonhuman animal - again, irrespective of their mental capacities?

Typically, defenders of experiments on animals do not deny that animals suffer. They cannot deny the animals' suffering, because they need to stress the similarities between humans and other animals in order to claim that their experiments may have some relevance for human purposes. The experimenter who forces rats to choose between starvation and electric shock to see if they develop ulcers (which they do) does so because the rat has a nervous system very similar to a human being's, and presumably feels an electric shock in a similar way.