There’s an ancient question, known in philosophy as Euthyphro’s Dilemma. Asked by Socrates in the Platonic dialogue Euthyphro, the question goes:
“is the pious loved by the gods because it is pious, or is it pious because it is loved by the gods?”
Later on in the history of philosophy, these two positions came to be called natural law and divine command theory. The essential question is how we know what is right. Does God teach us how to live through scripture? Or did He give us the room to observe the world and use reason in order to discover how we ought to behave? Can both be true?
Catholic philosophers in the Middle Ages, like Thomas Aquinas, developed a robust “natural law tradition.” For them, the Bible exists to remind us and illustrate for us what we should already know, which is to say, the natural law. It’s a “cheat code” to tell us what we should know, if we were all true and flawless moral philosophers.
But what does the Bible say about all of this? Does it believe in natural law? Well, it definitely seems like it does. Sure, God gave a body of laws to the Israelites. But the Israelite prophets, who are sent to set their people on the path to a right relationship with God, talk about much more than obeying the law. Specifically, the prophets do not see moral obligations as only emanating from God.
For example, Amos 1:3-2:3 denounces the war crimes committed by Israel’s foreign neighbors, among them the Philistines and the Moabites. However, none of the offenses they are criticized for committing are mentioned in Biblical law! Rather the prophet is saying that you nations should have/ought to have known that it’s unacceptable to enslave or torture your enemies in war.
Amos says that God will punish these nations for their cruelty, and thus seems to assume that they know such acts are wrong even without a divine commandment!
Isaiah, a contemporary of Amos, inveighs against the pride of Judean kings who trust in their armies more than in the Lord. Again, there is no Biblical law being broken here, but the pride of kings, which usurps the true God by making kings desire to be like God, is a sin. Not because God has forbidden it, but because, as John Barton put it in his book, it “misunderstands the place of human beings in the world order. It represents a self assertion which wants to overturn the proper order of things for selfish motives (Barton 63).”
Isaiah also criticizes sins like drunkenness and gluttony (see Isaiah 5:22), which are not forbidden under biblical law. The people aren’t supposed to accept Isaiah’s criticisms because he was revealing new divine laws, but rather because they have a natural moral sense and can intuit why certain legally permitted acts are sinful.
Natural law is about people recognizing their “finite, created status and seeking a way of life which embodies their sense of belonging in the hierarchical universe whose head and origin is God (Barton 67).”
Of course, though, we can’t forget that Israelites certainly believed that God had issued decrees for them to obey. Obedience is about loyalty to God and to the covenant that the Jewish people made with God when they chose at Mount Sinai to become His nation and live by His laws (see Exodus chapter 19).
Thus, the prophets (like Isaiah in chapter 1) also emphasize that Israel’s sins aren’t just bad because they violate natural law, but because they disobey God, who is compared to our spouse, and thus demands our spousal loyalty.
I’m not exactly sure what to do with all of these pieces of evidence that point in so many different directions. If you have any insight into the biblical texts or the philosophical issues, help me out in the comments!