There are several versions of the moral argument for theism.[i] One goes like this:
- If God does not exist, then objective morality does not exist.
- Objective morality exists.
- Therefore, God exists.
(This argument is deductively valid by modus tollens.)
Suppose a friend asks you why he should believe in God. You share the version above with him. Thus begins the dialectic. He accepts (1). However, he is like some of the college students in an introductory ethics class that I teach: he believes that morality is merely subjective.[ii] Hence, he denies (2) and asserts (4): Morality is subjective. How might you respond?
Well, you could defend (2). There are reasonable arguments to support the claim that morality is objective. But let’s say that your friend sticks to his moral subjectivism. What then? You could grant (4) arguendo. Why do such a thing?
Remember, your friend asked for a reason to believe in God, not for an argument to support objective morality. Since your friend is a resolute moral subjectivist, you might ask him to consider the nature of subjectivity. If something is subjective, its existence depends on the human mind (i.e., on human states of consciousness such as thoughts, beliefs, or desires). For example, Smith’s desire to eat ice cream is subjective. Smith’s nonexistence would entail the nonexistence of his desire for ice cream.
Now, notice that subjectivity requires consciousness. Thus, your friend is committed to affirming the existence of consciousness.[iii] Here, the dialectic takes an interesting turn. Arguably, theism is the best explanation for the existence of consciousness.[iv] As such, you can argue as follows:
- Morality is subjective. (Granted arguendo)
- If morality is subjective, then consciousness exists.
- If consciousness exists, then God exists.
- Therefore, if morality is subjective, then God exists. (5, 6 HS)
- Therefore, God exists. (4, 7 MP)
Your friend is committed to (4). (5) is analytically true. (6) is plausible. Thus, your friend’s moral subjectivism gives him a reason to believe in God. And that’s just what he asked for in the first place.
[i] For a detailed commentary on several versions of the argument, see Moral Arguments for the Existence of God by C. Stephen Evens at https://plato.stanford.edu/entries/moral-arguments-god/
[ii] Each term, a significant percentage of my students start the course by claiming that morality is subjective. They tend to be moral subjectivists in either (a) a cognitive sense or (b) a non-cognitive sense. According to (a), the truth of a moral proposition depends on the beliefs or desires of the subject who asserts that proposition. According to (b), moral utterances are neither true nor false, and thus not propositions at all. Rather, they are merely expressions of emotion. This view is sometimes called emotivism.
In Act 2, Scene 2 of Hamlet, Shakespeare has Hamlet say: “There is nothing either good or bad, but thinking makes it so.” (http://shakespeare.mit.edu/hamlet/hamlet.2.2.html) This is a pithy characterization of moral subjectivism.
After about two weeks of examining the meaning of subjectivity and the implications of moral subjectivism, many of my students become skeptical of their moral subjectivism. They realize that they don’t proceed very far in their moral thinking or dialogue before making assertions of moral objectivity, thus being compelled to forsake their subjectivism.
[iii] And who would deny the existence of consciousness, anyway? Surprisingly enough, some have ventured into that quagmire. Most are sufficiently conscious to avoid it.
[iv] This thesis has been rigorously defended by J. P. Moreland in The Recalcitrant Imago Dei: Human Persons and the Failure of Naturalism (London: SCM Press, 2009) and in “The argument from consciousness,” The Blackwell Companion to Natural Theology, eds. William Lane Craig and J. P. Moreland, (Oxford, Blackwell Publishing, 2012). For example, consider this argument from pages 22-23 in The Recalcitrant Imago Dei. See the book for Moreland’s defense of the premises.
- Genuinely non-physical mental states exist.
- There is an explanation for the existence of mental states.
- Personal explanation is different from natural scientific explanation.
- The explanation for the existence of mental states is either a personal or natural scientific explanation.
- The explanation is not a natural scientific one.
- Therefore, the explanation is a personal one.
- If the explanation is personal, then it is theistic.
- Therefore, the explanation is theistic.