Aquinas on the binding of Isaac

Thomas Aquinas registers a possible objection to the fixedness of natural law, from the fact that “God commanded Abraham to slay his innocent son [Isaac]”, that he ordered the Israelites to “borrow and purloin the vessel of the Egyptians” in the Exodus, and that he commanded Hosea (or, Osee) to take Gomer the whore for a wife.

He answers that the natural law can be changed by way of some additions being made to by divine law and by human law; he also concludes that the natural law can be changed insofar as the secondary principles of natural law can be changed as a particular circumstance might require.

He then replies to the objection noted above. Aquinas gives the Israelites a pass on their purloining, arguing that all things belong to God, and that if God wills for them to take these goods, they have not stolen from him. Perhaps. Surely an easier way around this is exegetical: the plundering of the Egyptians does not even seem to be contrary to the will of the Egyptians themselves, as the Israelites “asked” for these goods (Exodus 12:36). Admittedly, the word can have the sense of “borrow”, but it isn’t clear from the narrative that the Israelites intimated to their neighbours that they would bring these things back to them.

As for Hosea, Aquinas answers that a man’s wife is the wife “allotted to him by the law emanating from God”. God gave Gomer to Hosea; therefore, Gomer is Hosea’s wife, and that’s that. This struck me as strange, not least because I’m not familiar with any reading of Hosea that understands him to be taking a wife already married to another man, but rather, he takes a woman of ill repute. On that view, Hosea would have done something that is morally lawful with or without a special command of the Lord (just as Salmon did, in marrying Rahab) even if it would ordinarily be foolish to do so without such a command. Again, the passage itself does not appear to invite this exact moral quandary.

(The answers to these two questions also struck me as quite divine command theory-ish, as though God can simply declare that certain things are just or right.)

But there is significant force in the problem with Abraham and Isaac, and truthfully, I don’t think Aquinas’ solution quite works. He answers that, because of original sin, all men are due to die the death of nature anyway, and that God can command a man to kill another man at any time without any injustice. The commanded man would be acting as God’s instrument, on that view. The problem, of course, is that the command in Genesis 22 is not presented to the reader as for Isaac’s sins. It is trivially true that, as a descendant of Adam, he is guilty of sin, but that is not what the killing is said to be for. (In fact, God doesn’t tell Abraham what it is for at all.) We might contrast this command with God’s later command to Israel to kill women and children of Canaan. In that case, Israel functions as God’s instrument for judging them for their iniquities (cf. Gen. 15:16).

Perhaps, perhaps we could say that God has altered the secondary principles of the natural law, that is, how the primary principles of natural apply to particular circumstances. Still, one struggles to see what about the particular circumstances would justify this modification of a most basic principle of natural law.

No answers here, I’m afraid. More thought is needed—and perhaps I should re-read Kierkegaard’s Fear and Trembling.