Why are most philosophers moral realists? [duplicate]

Question

I’m having trouble understanding this. Moral realism is the position that morality is independent of subjective opinion. But how can this be if only we care about what’s moral? Lions are ripping other animals’ heads off and nature doesn’t care. So why should we?

Any argument that I’ve seen for moral realism seems to beg the question and yet I see 50+% of philosophers still believing it. I can’t seem to even think of a way to make this make sense. Can someone enlighten me if I’m missing out? This kind of reminds me of how there are scientists that say certain particles don’t have objective attributes until you measure them, such as in quantum mechanics. To this day, I haven’t seen an argument that explains what they mean. How can reality not be objective?

So what do people mean when they say that moral facts are independent of subjective opinion?

Answer 1

Perhaps you're projecting your definition of moral realism—"morality is independent of subjective opinion"—onto other people who apply the phrase "moral realist" to themselves. As the IEP entry on moral realism states:

... we succeed in knowing certain moral judgments to be true. Moral realism implies some sort of literal success theory, and so moral knowledge is implied by it. Or, moral realism entails at least the possibility of such knowledge.

Now if knowledge is justified true belief ("plus some fourth thing," as they say), the above comes out to: "A moral proposition can't be true unless it is possible to have a subjectively justified, and true, opinion about it." So there is some peculiar dependence on subjectivity and opinion-formation even in moral realism. One will say, "That's not the kind of dependence I meant!" but so then I must caution that the matter is still not entirely clear.

The popularity of some sort of moral realism is grounded in a variety of overlapping considerations: there is the question of the normativity of meaning and content in general and the sister notion of metaepistemological realism, for instance. But you also have e.g. John Rawls' account of his theory of justice as objectivity-minded (A Theory of Justice §78):

[The principles of justice] are the principles that we would want everyone (including ourselves) to follow were we to take up together the appropriate general point of view. The original position defines this perspective, and its conditions also embody those of objectivity... Thus our moral principles and convictions are objective to the extent that they have been arrived at and tested by assuming this general standpoint...

And so they are somewhat "objective" questions, "Does action X promote the greatest balance of happiness over suffering?" or, "Does action X accord with the categorical imperative?", etc. (despite the subjectivity involved on other levels, of course). Since utilitarianism, Kantianism, divine-command theory, and so on are both individually and cumulatively popular enough, so will be a sense of moral questions as (sometimes, to some degree) "objective."