Sean Carroll in Preposterous Universe:
Despite occasional and important disagreements, most people are in rough agreement about what it means to be moral, to do the right thing. There’s much less agreement about why we should be moral, or even what kind of answer to that question could be convincing. Philosopher Russ Shafer-Landau is one of the leading proponents of moral realism — the view that objective moral truths exist independently of human choices. That’s not my own view, but ethics and meta-ethics are areas in which I think it’s wise to keep an open mind and listen to smart people who disagree. This conversation offers food for thought for people on either side of this debate.
More here.