We do not have to make self- sacrifice a necessary element of altruism. We can regard people as altruists because of the kind of interests they have … - Peter Singer

It is now generally accepted that the roots of our ethics lie in patterns of behavior that evolved among our pre-human ancestors, the social mammals and that we retain within our biological nature elements of these evolved responses. We have learned considerably more about these responses, and we are beginning to to understand how they interact with our capacity to reason.

To protest about bullfighting in Spain, the eating of dogs in South Korea, or the slaughter of baby seals in Canada while continuing to eat eggs from hens who have spent their lives crammed into cages, or veal from calves who have been deprived of their mothers, their proper diet, and the freedom to lie down with their legs extended, is like denouncing apartheid in South Africa while asking your neighbors not to sell their houses to blacks.

Human beings are social animals. We were social before we were human.