Christian ethics often appeals to two sources for moral truth: natural law (truths accessible through reason and observing the created order) and special revelation (truths revealed directly in Scripture).

How should a conflict between these two be resolved? For example, when Old Testament commands (e.g., the injunction to annihilate the Canaanites in Deuteronomy 7) appear to directly violate a rationally derived natural law principle against killing non-combatants, which source takes precedence? On what theological grounds is this hierarchy justified?