I've been working through Huemer's recent book Ethical Intuitionism, and I've overall been finding it to be exceptionally clear and well written, especially compared to a lot of other metaethics and moral epistemology I've read.
Huemer raises a series of objections to Divine Command Theory (DCT), the view that "that right actions are right only because God commands them" (p. 55). His second objection is as follows:
How do we know what God approves of?... According to Western religious tradition, we can know God's desires from such sacred texts as the Bible... But in fact, this source of guidance is notoriously unreliable. The moral guidance to be found in the Bible includes the following imperatives (my paraphrases)
Kill anyone who curses their parent. (Lev. 20:9)
Kill anyone who commits adultery (Lev. 20:10)
Kill homosexuals (Lev. 20:13)
Kill women who have premarital sex (Deut. 22:20-1)
Kill people who work on the Sabbath (Ex. 35:2)
Make war on people occupying the promised land. Show no mercy; kill every man, woman, and child. (Deut. 7:1-2; 20:16-17)
Slavery is okay (Lev. 25:44-5)
It is okay to beat your slaves, as long as they don't die. (Ex. 21:20-1). (p. 55)
All the commands except the sixth are dictates for how the Israelites should treat each other. Israel has made a covenant/contract with God agreeing to following these commands. Huemer takes it as obvious that one ought not to do the things listed here. However, given that such a covenant exists, and the not implausible premise that God has the right to decide when a person's life ends, I don't take these commands to be obviously flawed. Am I incorrect?
Secondly, suppose the Bible is unreliable. Suppose other religious texts (Huemer also discusses the Quran) are unreliable. He then writes,
The problem is that this would leave it mysterious how we can know what God wants, thereby threatening our capacity for moral knowledge... The Divine Command theorist would have to posit some sort of access to moral facts independent of our knowledge of God's will, which would seem to surrender one of the major advantages of a Divine Command theory - namely, it's ability to explain moral knowledge. For example, the Divine Command theorist might be driven to posit a faculty of moral intuition - but then it is unclear how his theory would be better than traditional ethical intuitionism. Or the theorist might adopt one of the proposals of recent ethical naturalists (p. 56, my underlining).
I found this discussion odd. To give some background, Huemer takes ethical intuitionism to have both a metaphysical component (that moral properties are objective and irreducible) and an epistemological component (that we can know moral truths by way of intuition) (p. 6).
DCT, as he defines it, is the metaphysical claim that moral facts are reducible to divine-command/approval-facts. Hence, DCT conflicts with the metaphysical component of ethical intuitionism. But since nothing in DCT implies anything at all about epistemology, it's odd for Huemer to bring up these epistemological objections in the first place. If there is a superiority to DCT, it will be in a difference between the two theories, but that can only be in their metaphysical differences, not differences in epistemology (since DCT makes no claim about epistemology). So, why not think that the DCTers can know moral truths on the basis of something like intuition? Furthermore, it is odd that he says that the DCTer is driven to posit a faculty of moral intuition. I would think most DCTers, especially Christians, would believe in something like a faculty of moral intuition (see Romans 2:15). I guess I don't see any problem in the neighborhood here. However, I see more plausibility in the claim that something is wrong with the above divine commands.