I take the view that morality is herd instinct in the individual, and that it is more productive to look at it as a sociological phenomenon instead of resurrecting platonic idealism. Whatever the herd deems good is Good, whatever the herd deems evil is Evil. There is no objective morality written on stone tablets that we can consult to determine that torture is Evil or that killing animals is wrong. That's why we have plentiful examples of cultures throughout human history, composed of intelligent, thoughtful people, who saw absolutely nothing wrong with torture.
This 'herd instinct', by evolutionary necessity, will tend towards in-group altruism in any social animal, but the details, the bylaws, and everything else will be driven by accidents of history and by fashion. It may be that one day that the great human herd of western civilization will collectively decide that eating meat is evil; I sure hope not, I prefer our current fashions (but then I would, having grown up with them.)