Mailbag: Arguing for the Premises of the Moral Argument

I had a few questions regarding the following argument:
1. If there is moral obligation / knowledge / transformation, then God exists. (Theistic Metaethical Theory)
2. There is moral obligation / knowledge / transformation. (Moral Realism)
3. Therefore, God exists.
Is there a way to argue for this in a succinct way or are 1 and 2 separate arguments in and of themselves?
Evans in "God and Moral Obligation” argues roughly for 1 (he limits it to moral obligation). And arguments in response to people like Joyce are needed to establish 2.
Is your adductive argument as you lay out for 1 and your forthcoming book is aimed at 2?
Kevin

Hi Kevin, thanks for this. Yes, I think you’re quite right. So yeah, this modus ponens version of the argument is a popular way of putting the argument(s). As you note, I prefer an abductive approach for several reasons, one being that the contrapositive of the first premise above involves what I consider to be a counteressential: a situation in which God doesn’t exist. If God exists necessarily, as I think he does, then we’re literally envisioning an impossible world, indeed a null world. So to ask of such a world what its features are strikes me as problematic.

Both deductive and abductive versions, though, begin with moral phenomena realistically construed. So the second premise requires a defense of moral realism. This is the book in the tetralogy that Jerry and I haven’t written yet, yes, but we just got a contract with OUP to write it, which is exciting. We will argue against error theory, expressivism, constructivism, etc., and try to answer debunking objections (this is where Joyce comes in, exactly right, along with folks like Kahane, Ruse, Street, etc.). Of course we’ll also attempt to provide several positive reasons to believe in moral realism.

The first premise requires that the theistic explanation be shown explanatorily superior to the secular alternatives. So it involves two tasks: defending theistic ethics against objections (and giving positive reasons for it), and critiquing secular ethics that attempt to make sense of moral realism. Good God was on the first topic, and God and Cosmos was on the second.

I think quite separate arguments are needed, then, for the two premises in question. Defending moral realism logically comes first (though we’re getting around to it last), and then the case for the comparative superiority of theistic ethics.

Evans makes the case for both premises (delimited, as you say, to moral duties)—why theism makes such good sense of them, why we have reason to believe duties are real in the first place, and the limitations naturalistic accounts encounter making sense of them.

Our abductive argument, too, makes the case for both premises (though the second premise would be couched in terms of best explanation). There really are three tasks, again: defending moral realism (current book), defending theistic ethics and arguing in favor of it positively (Good God), and critiquing secular ethics (God and Cosmos). A yet fuller case would expand that last point to include a critique of nonChristian religious ethics, which I haven’t done, but some students are working on (taking on Islam, Mormonism, etc.). It’s something I hope to do more later, especially Buddhism, Hinduism, and Islam.

Does that help?

Merry Christmas, friend!

Blessings,

Dave