Remember the Euthyphro dilemma? Plato’s dialogue depicts Socrates as asking “whether the pious or holy is beloved by the gods because it is holy, or holy because it is beloved of the gods.” Socrates goes on to wonder whether the essence of piety could ever be discerned by relating it to the gods.

The Euthyphro dilemma for the Greeks stayed relevant to Christianity, because medieval Christians understood morality as essentially related to god (for example, according to the divine command theory of ethics).

Socrates’ question can be phrased as a challenge to any religious view of morality that wants to guarantee that morality is stable by making it depend on a god. Here’s an example of how to make this challenge. Suppose morality does depend on a god. Now consider this dilemma: Either something is morally right because god makes it so, or god makes it right because it is moral. If something is right because a god makes it so, then god could possibly change it (for all we know), and then the right could instead be the wrong. On the other hand, if a god makes something right because that is moral, then morality is independent of god (and maybe people don’t need any god to know morality).

To avoid the second horn of the dilemma, the religious theory of morality must run into the first horn, and admit that morality could have been different, and therefore this theory can’t really guarantee the stability of morality. The dilemma therefore explodes this religious theory, because on either horn, the theory can’t actually deliver the stable morality that it promises.

It’s only natural that religious theologies would try to avoid this nasty dilemma. Here is a common way: Declare that god cannot change morality, because morality is so fixed to god’s unchanging essence that god would never make morality other than what it is.

A different mode of criticism is now needed. I think that a second dilemma can be applied to demolish this theological strategy. Let’s recall Fyodor Dostoevsky’s classic work The Brothers Karamazov , in which the brothers debate God’s existence and whether God’s creation could really be as morally perfect as the faithful believe. Some of those debates (especially in Book Five) bring up the modern problem of evil: How could a perfect, all-good God permit evil in the world? The modernist theological answer, expressed at a couple of points by the more pious brother, is that every apparent evil must actually be good from God’s unchanging perspective, but we are too ignorant to understand how. The skeptical brother is not impressed by this answer.

Once again, a religious theory of morality tries to guarantee that morality is perfectly fixed by a good god. But the modernist appeal to human ignorance has curious consequences, which Dostoevsky noticed. Christianity has always promised that we could know what morality is, because of God. But modernist theology, chased by Socrates, has been forced to save religious ethics by claiming that humans must be largely ignorant about god’s moral plan for creation. This confession of ignorance drives Christianity straight into Dostoevsky’s question: Why should I have to surrender my understanding of good and evil to be religious? Wasn’t religion supposed to guarantee knowing good from evil? I think that Dostoevsky’s dilemma has driven religious ethics into another dead-end.

Christianity promises that we can know right from wrong through God. But we can’t know God directly, according to modernist theology. We only have what God creates (such as nature, revelations, Jesus, the Bible, etc.) to rely on for our knowledge of good and evil. Now let’s additionally suppose God’s creation is morally perfect – everything that happens is good in God’s eyes. Christians would love to believe these two things: (1) God’s creation is responsible for our ability to tell good from evil, and (2) God’s creation is morally perfect.

Here is where Dostoevsky’s dilemma hits Christianity: Either we can know good from evil in the world by looking at God’s creation, or we can know that all of God’s creation is completely good. On the first horn of this dilemma, we can know that there are real evils in creation by observing them, and therefore God is responsible for creating evils – you can’t trust God on right and wrong. But on the other horn of this dilemma, we can know that everything in creation is perfectly good, but then we would lose any distinction between good and evil – you can’t identify any evils at all. It’s all good.

Pick the first horn of Dostoevsky’s dilemma: God can’t be trusted on good and evil. Or, pick the second horn of his dilemma: You can’t be trusted on good and evil. Either way, religion can’t be any help with knowing good from evil. And there are no more theological escapes to be found, after the dilemmas of Socrates and Dostoevsky. Religion must get out of the foolish business of making knowledge of good and evil dependent on a God.