Another Christian Apologist Tears Down a Straw Man of Atheist Morality

My friend Wintery Knight (WK) has written another blog post on the topic of morality. Like so many other theists (and a few atheists), he manages to completely botch the topic of atheist morality.
Who Speaks for Atheists, Anyway?
If you want to determine Christian beliefs about something, you can see what the Bible and various representatives of the (Christian) church hierarchy have to say. So if you’re a Christian apologist trying to make sense of atheist morality, it follows that you should see what the Atheist Bible and various representatives of the (atheist) church hierarchy have to say. Right?
Wrong! There is no atheist Bible or hierarchy, so you’re going to have to do better than quote mining various atheists, even famous atheists. You’re even going to have to do more than write snarky summaries of your favorite debates between William Lane Craig and his (typically) clueless-atheist-debate-opponent-of-the-month. You’re going to have to temporarily stop bashing non-STEM degrees (see, for example, here) and actually study ethics (specifically, meta-ethics) and construct deductively valid or inductively correct arguments to support your claims. As we shall, however, WK fails to do this.
Rationally Grounded Morality
WK begins his post by listing 5 requirements for a “rationally grounded system of morality”:
(1) Objective moral values
(2) Objective moral duties
(3) Moral accountability
(4) Free will
(5) Ultimate significance
After reading his comments on these five requirements, I thought to myself, “He could have been much more concise by simply stating that a rationally grounded system of morality must be personally approved by William Lane Craig or, better yet, require that God exists.” If that seems snarky, it’s not meant to be. WK’s comments really are that question-begging. The fact of the matter is that WK has confused rational grounding with a plethora of other topics.
Regarding (1) and (2): Like WK, I consider myself a moral objectivist, but I think it’s a blatant straw man for WK to claim that a “rationally grounded system of morality” requires objective moral values and duties. An ontologically objective system of morality requires those things, but I don’t think a “rationally grounded” system of morality does. At the very least, WK has given absolutely no reason to think that it does.
Item (3) suffers from similar problem. WK has confused the grounding of morality with motives and reasons for moral behavior. Whether there are ontologically objective moral values and duties is logically independent of whether there is moral accountability.
Turning to (4), he simply begs the question against both determinism and compatibilism (the latter entails that moral accountability is possible even if determinism is true). For the record, I don’t have a position on the free will vs. determinism and compatibilism vs. incompatibilism debates. But to write as if no one has given any serious arguments for compatibilism is simply irresponsible and, I daresay, immoral.
As for (5), WK confuses the grounding of morality with the topic of the meaning of life. As I’ve argued before (skip down to the end of the linked post):

This claim confuses the distinction between purpose and value. 
To say that something exists for a purpose means there is a reason for its existence.  To say that something has value means that it has desirable characteristics.  Even if something was not created for a purpose, that thing can still have value if it has desirable characteristics.  Moreover, in order for a thing to be valuable, it does not have to be valuable to the person or thing that created it.  Therefore, although the human species was not created for a purpose (and so is not valuable to the impersonal forces of evolution), the human species is still valuable because it is valuable to humans: individual humans desire the existence of the human species.
Objective moral values and obligations do not depend on a ‘cosmic telos‘ or external purpose for the universe’s existence.

In fact, one may not unreasonably conclude that WK hasn’t given an argument for why a rationally grounded system of morality requires ‘ultimate significance’. Rather, he’s simply expressed his subjective desire that our lives have ultimate significance (in his sense). Furthermore, as John Danaher has summarized, Toby Betenson has written a forceful, internal critique of WLC’s claim that theism accounts for the significance of life.
Finally, although I’m not going to attempt to defend a complete list of desirable characteristics for a system of morality, notice what WK left out of his list. His list says nothing about moral epistemology. But if you think about it for a moment, what practical difference do objective moral values and duties ‘out there’ make, if human beings have no reliable method of knowing what they are? In fact, moral epistemology, as a whole, favors naturalism (including atheism) over theism. Why? Because naturalism explains moral disagreement much better than theism does.
Quote-Mining, Anyone?

WK then proceeds to quote three atheistic biologists who support his claims: Coyne, Provine, and Dawkins. (I’ve commented on each before; see here.) But, in what is becoming all too typical of Christian apologists, what we don’t find is any interaction with philosophers, especially those who specialize in metaethics–including both theists and nontheists–who reject his claims. These people include:

He also ignores the work of atheist philosopher Alonzo Fyfe (who is ABD) and who developed the theory of desirism. WK also ignores John Danaher’s formidable critiques of WLC’s arguments (see, for example, hereherehere, here, here, here).
In short, WK hasn’t even come close to charitably interacting with atheist morality.
A WLC-Style Case for the Autonomy of Ethics
Since WK is such a fan of WLC’s debates, I’d like to close this post with a WLC-style case for the autonomy of ethics, i.e., why ethics doesn’t (ontologically) depend on God.
First Contention. There are no good reasons to think ontologically objective moral values depend on God.
(1) The “laws require a lawgiver” argument is a weak reason to think that moral laws require a moral lawgiver.
(2) The “I can’t see how morality could have an objective ontological foundation without God” argument is a weak reason to think that morality cannot have an objective ontological foundation without God.
(3) The “I can selectively quote some famous atheists who agree with me” is a weak reason to think that morality without God is subjective. (Cf. here, here)
(4) The “Darwinian naturalism entails that morality is nothing but a biological adaptation” argument is a weak reason to think that morality without God is nothing but a biological adaptation.
(5) The arguments in (1)-(4) are representative of the kinds of arguments used to justify the claim that God is required for a rationally grounded system of morality.
(6) Therefore, there is no good reason to think ontologically objective moral values depend on God.
Second Contention. There are good reasons to think ontologically objective moral values depend on God.
1. In order to determine if objective values exist, one must first:
(a) have a rigorous definition of “objective values”;
(b) determine whether ontologically objective values require a ontological foundation; and
(c) determine if there are nontheistic ontological foundations available.
2. If objectivity is defined epistemologically, God isn’t needed for objective values.
3. If objectivity is defined ontologically, God isn’t needed for objective values. This is because:
(a) it’s far from obvious that ontologically objective moral values require an ontological foundation (some such values could be brute facts); and
(b) if they do, nontheistic foundations are available.
4. Therefore, ontologically objective moral values do not depend on God.