I thought this was an excellent answer. It came from a recent interview at The Freethinker:
It is actually very easy to identify and to act upon the moral baselines. Moral baselines derive from our understanding of what it is to be human and what human beings need to flourish. For example, at a minimum people need food, they need somewhere comfortable, dry and warm to be, they need friendship, they need opportunities to use their intelligence, because we’re a highly intelligent species. People need opportunities to develop, they need time to rest and benefit from the creativity of leisure, they need safety, and they need social bonds.
We know all these things, and if you look at human rights instruments like the Universal Declaration of Human Rights, what they say is what the minimum requirements are for opening a space around individuals, so that they can use their abilities to do things that are good and satisfying for them.
So this very basic understanding of what it is to be human, along with what we dislike, what we want to avoid, what we need, what we benefit from, tells us something about what our obligations are to other people.