Metaethics asks questions like: Do moral facts exist? What form do these facts take? How do we know about them? CAN we know them? Do moral judgments express beliefs or emotions? etc.
I just recently started studying this topic, so I’d like to see what I’ve learned. Here are a few different positions to take in metaethics. Different theories will espouse different views, naturally.
Cognitivism is basically the view that our moral judgments express beliefs. Beliefs are either true or false, so our moral beliefs can also be true or false. An interesting and counterintuitive view that seems to take the cognitivist view is Mackie’s error-theory, which states that our moral concepts are concepts of objective, prescriptive facts about the world which do not, in reality, exist, so we are literally in error on our moral beliefs.
Non-Cognitivism says that our moral judgments express emotions, sentiments, desires, etc., which are all non-cognitive. Since they are not beliefs, they are not true or false in the sense that they correspond to some reality external to us. It’s similar to how stepping on a bee and yelling “OUCH!” has no truth-value to it. Emotivism is an example of this view.
Naturalism states that moral properties are basically natural properties. Moral properties are instantiated by a natural state of affairs. A person holding this view might say that what is “good” is what leads to the greatest happiness for the greatest number.
Non-naturalists believe that moral properties are not natural, hence the name. Moral properties may take the form of the Platonic forms mentioned by Plato, or as the commands of God mentioned by Divine Command Theorists.
This is my understanding of the views so far. I look forward to studying metaethics more.
Miller, Alexander. An Introduction to Contemporary Metaethics. Cambridge, UK: Polity, 2003. Print.