This is the the twenty-third post in my Theories of Knowledge and Reality series. Follow the link for more on the series and for links to other entries as they appear. In the last post, I finished discussing the design arguments for the existence of God, and this post begins looking at moral arguments for God's existence.
[Note: These posts on the moral argument are derived in part from discussions in Gregory E. Ganssle, Thinking About God and C. Stephen Evans, "Moral Arguments" in A Companion to Philosophy of Religion, ed. Philip L. Quinn and Charles Taliaferro.]
According to naturalism, the natural world is all there is. There are subatomic particles, waves, fields, etc. There's no room for God, souls, magical forces, angels, demons, a world-spirit that orders all creation, or anything like that. The natural world known to us through physics (and disciplines building on physics, e.g. chemistry, biology, psychology, economics, history, etc.) is all there is, and we shouldn't postulate the existence of anything else.
How can a naturalist account for morality? Consider what you learn from science. You won't find moral truths. It's not as if there are moral facts out there in the physical world together with facts about brain chemistry or nuclear physics. It's hard to find a place to fit morality in. Many theists think an account of morality that seeks to rely only on the natural world will be inadequate, superficial, or illusory. The deep kind of morality most of us believe in requires denying naturalism in some way.
Consider some particular naturalistic accounts of morality.
Evolutionary Theory of Morality:
The first naturalistic theory about morality is basically a denial of morality. It says we have these beliefs because those who had them tended to survive better (though that doesn't quite explain their origin). Survival advantages do seem to be good for us. But morality is an illusion if this view is correct, and there really is no subject matter for them to be about. We simply believe false claims whenever we believe things about right and wrong. This view basically admits that naturalism won't allow moral truths.
Some people think this is too extreme or find moral truths so intuitively compelling that they need to keep them somehow. There isn't much of an argument against this view besides practical considerations or thinking we have some kind of direct, intuitive access to moral truths (maybe a priori knowledge), but it doesn't tend to be a very popular view once it's clear what it amounts to.
This view says that there are facts in the natural world that are the subject matter of our moral claims. They're just facts about our own desires and feelings, not about any independent truth. A problem with this view is that our moral beliefs go against our feelings of obligation (e.g. we should be honest on taxes, but many people don't feel any obligation). On the average college campus, you can find a noticeable percentage of students who believe it's wrong to engage in certain activities (e.g. sex outside the context of marriage, drug use, etc.) yet have no feeling of obligation to avoid doing so. Also, we may feel obligations we often would say we don't really have (e.g. a wife who feels obligated to stay with her husband who regularly abuses her). So what we believe are moral truths don't match with what obligations we feel. Then they can't be the same subject matter.
This view also doesn't allow for moral disagreements. It does allow for people to say things that are opposites, but it's like saying that coffee tastes good and someone responding that it doesn't. It's not like saying that the sky is blue with someone responding that it's not. The second case is a genuine disagreement about the facts about the makeup of the sky and how it reflects light. The first is just a matter of preference. Moral arguments don't seem to be disputes about preference in a way that would allow for both sides to be right. We don't seem to treat them that way, anyway.
But perhaps the most common reason why people might resist this view is that it makes what's morally true depend just on what people happen to think, and I don't think most people really believe that. Most people take moral truths to be independent of what we happen to think. In extreme cases, that becomes very clear. Very few people think that torturing infants for the fun of it becomes ok just because someone takes it to be ok.
Cultural relativists take right and wrong to be determined by culture. If a culture takes something to be good or bad, it's good or bad for people in that culture. Statements about right and wrong are made true by the fact that the culture as a whole approves or disapproves.
The first difficulty is in figuring out what counts as a culture and then determining which culture one belongs to is what counts for moral truths (e.g. if I am Roman Catholic and Canadian, which one wins out when the dominant Canadian view is pro-choice and the dominant Roman Catholic view is pro-life?) Perhaps that difficulty can be overcome with a sophisticated theory of the interaction of different cultural interests, but it is a difficulty this view would need to deal with.
Cultural relativism also doesn't allow for moral heroes who stand up against their culture. Abolitionists would have been doing something immoral, as would those who refused to go along with Hitler's regime.
The most commonly offered problem for cultural relativism is similar to the major problem with individual relativism. It's that most people don't actually believe this, even if they initially find the view attractive. That becomes clear again with the most extreme cases. Very few people think something like the kind of slavery practiced in the United States into the 19th century or the Holocaust could possibly be morally ok. Yet in both cases the culture approved of it, and thus a cultural relativist should say the practice would be ok for them. Perhaps the cultural relativist could respond that there swere other views held by the culture in question that made it wrong, e.g. the U.S. Constitution's statement that everyone is created equal. But this is only a technicality. It seems that a culture could arise that fully endorsed some practice without any hints in the culture that it goes against some deeper principle they hold to. Most people wouldn’t consider that enough to make it right for them.
If there are moral truths, and they are not just about individual people's attitudes or the attitudes of cultures, then they must be truths independent of what people happen to think. This general category of views is often called objectivism. An objectivist need not think every moral question has the same answer in every case, but the core view is that some moral truths are true because of things outside our own preferences or the facts of our culture.
Some objectivist views take morality to be based on facts about pleasure, pain, happiness, or unhappiness. Others take us to have fundamental rights, and all of morality is then grounded in that. The difficulty with seeing this as a naturalistic theory is that it still assumes something naturalism doesn't explain. What makes pleasure or happiness good? What makes pain or unhappiness bad? According to the evolutionary theory of morality, there is no such thing as goodness or badness except that we have fictional beliefs about such things. So it seems coherent to have a view according to which happiness, unhappiness, pleasure, and pain exist and yet they are not bad. So what is it that explains why they are bad? Can that be grounded in a naturalistic picture of the universe?
Similarly, what explains rights? Rights are supposed to be the foundation of morality, but what makes it true that we have rights? Can that be grounded in a naturalistic picture of the universe? One try is to say that complexity of thought, emotions, reflection on moral issues, and ability to make plans might give rights. But then we have taken the question back a step. What makes those things the kind of thing that gives rights? According to the evolutionary theory of morality, those things occur without any real rights. So what is it that’s supposed to explain why those things give rights?
This leaves a lot of people thinking that moral truths are somehow above and beyond the natural world. That does seem to be a denial of naturalism, so if someone has agreed with all the steps of the argument so far, then at least it's an argument against naturalism. But is it really an argument for the existence of God? Couldn't moral truths exist beyond nature without there being a divine being? In the next post, I'll look at the reasons some people have given for thinking of the explanation for morality as being something more like the traditional view of God.