I’ve focussed mostly on moral realism in these posts, but wanted to make a few brief comments about moral nihilism before I transition out of the subject of morality. I’m not going to get into the details of the different kinds of moral nihilism (you can read Wikipedia for that) – in this post I’m just using it as a term to describe someone who believes that objective moral truths do not exist.
First, as I’ve mentioned before, after I decided that I didn’t have enough reasons to claim belief in Christianity I pretty much became a moral nihilist. But I still had desires to live my life in the moral ways of compassion and empathy, and that was what I did. And even further, moral nihilists could hold to a very basic set of values and conclude that certain moral actions lead to the fulfillment of those values (although they might believe that this whole process is a very subjective one which I would agree with to a certain extent). I’ve discussed this sort of “practical” morality here and here.
As far as evidence against moral realism goes, there are examples from my own life that cause me to question moral realism as well. I was raised in a Jewish family and so violating the Mosaic laws brought on great guilt for me for many years of my life (even after converting to Christianity.) Eating pork is just one example of this (happens to be the popular example among Jews.) Turns out that believing that Jesus is God is an even better example – the guilt I felt when considering conversion to Christianity was quite strong. These guilt feelings really were no different than the guilt feelings I had or have when it comes to more common forms of morality. There really is no way of distinguishing between these guilt feelings (or if there is, I have never had the ability to do that.) This leads me to believe that our cultural groups can have a very strong impact on what we believe to be moral truths. I can see why this as well as evolutionary evidence could lead one to believe that there are no objective moral statements, but what I have been trying to express in these posts is that this is not at all a conclusion that we are forced to. Just because our cultures (or even evolution) can influence different people to contradictory conclusions about morality does not at all mean that there are not objective moral truths that somehow exist. Our cultures have also been able to influence different people to contradictory conclusions about how old the earth is, but this doesn’t force us to conclude that there is not an objective fact of the matter. It is quite possible that there are also objective moral facts of the matter. I am just not convinced strongly one way or the other.
Lastly, theists have a strange way of suggesting that moral nihilists are being “contradictory” when they mention anything related to “good” or “evil”, but this really isn’t the case. Some of this really just comes down to natural language and communication that is close to universally accepted. If someone punches you in the face for no reason at all, you don’t have to be a moral realist to say “that guy is a jerk” or even “that was wrong”, because those are statements that would be agreed upon by most everyone in our current societies. In this sense there really isn’t anything contradictory about moral nihilists using this kind of “moral” language. Now if they said that is just plain wrong in a cosmic sense, then of course that would be contradictory, but that isn’t what they mean when they talk in this way. Another related point is that moral nihilists could still rightly point out the internal inconsistencies of certain religions (such as terrorists harming unarmed civilians in the name of an all good God.)