This is a debate between me and SeekSecularism over the truth of the first premise of the following moral argument:
- If God does not exist, then objective morality does not exist.
- Objective morality does exist.
- Therefore, God exists.
- Opening Statements
- Maverick Christian
Maverick Christian’s Closing Statement
By descriptive ought I mean that type of ought that is nothing more than some purely descriptive state of affairs, e.g. “If you want to do well in school, you ought to study” meaning something like “As a matter of practical necessity, you need to study to do well in school.” By prescriptive ought I mean that type of ought that is not a descriptive ought, e.g. “You should not to torture infants just for fun.” By moral ought I (roughly) mean the prescriptive ought as applied to human behavior. For example, an action is morally wrong for someone only if they ought not to do it. When describing moral goodness and badness, SeekSecular defines “intrinsically motivating” as things that rational beings ought to (in the prescriptive ought sense) pursue in the case of moral goodness or ought to avoid in the case of moral badness. This too would be an example of a moral ought, particularly since this is attached to moral goodness and badness. By objective moral oughtness (OMO) I mean moral oughtness existing independently of whether we believe it to be so.
With the following symbolization key:
|M =||Moral oughtness exists.|
|A =||Atheism is true.|
|K =||The relevant background data.|
|Pr(not-M|A&K) =||The probability of M being false given A&K, i.e. the probability of moral oughtness not existing given atheism and the relevant background data.|
My overall argument can summarized thusly, where the Unbiased Atheist is someone who has no intuitions of moral oughtness existing or not existing, including not intuiting propositions that have moral oughtness’s existence implicit in them (e.g. the Unbiased Atheist wouldn’t have the intuition that Something is morally wrong is true or probably true):
|(P1)||If the Unbiased Atheist would be justified in believing Pr(not-M|A&K) is high, then Pr(not-M|A&K) is high.|
|(P2)||The Unbiased Atheist would be justified in believing Pr(not-M|A&K) is high.|
|(C1)||Therefore, Pr(not-M|A&K) is high.|
|(P3)||If Pr(not-M|A&K) is high, then Given atheism, moral oughtness probably doesn't exist is true.|
|(P4)||If Given atheism, moral oughtness probably doesn't exist, then the first premise of the moral argument is probably true.|
|(C2)||Therefore, the first premise of the moral argument is probably true.|
Lines (P1), (P2), and (C1) are more or less the Argument from the Unbiased Atheist (AftUA). The main purpose of the AftUA was to show that on atheism, people’s intuitions of moral oughtness existing are probably delusory and not veridical, which of course implies Pr(not-M|A&K).
(P1) seems true due to what K can and can’t include. K cannot include question-begging propositions like M is true or M is probably false, since then we wouldn’t really be answering the question at hand, which is how likely M is in the first place on atheism and not e.g. how likely M is given A and M is probably true. SeekSecular balked at the idea of the Unbiased Atheist being a good vantage point for the objective evidential relation between A&K and M, but given which sort of data is admissible for K, what more could one reasonably ask for than someone like the Unbiased Atheist, since any good-vantage-point atheist wouldn’t have the a priori intuition knowledge of moral oughtness existing?
My support for (P2) was the following inductive argument (with each premise predicated with, “If atheism is true, this is true:”).
- There is zero empirical evidence for objective moral properties. This supports the idea that the Unbiased Atheist has no good reason to accept M.
- It’d be a remarkable coincidence if moral intuitions happened to line up with what these invisible, causally inert moral properties are really like. Such reliance on remarkable coincidence suggests that we wouldn’t have real knowledge of objective moral truths; at best we’d have coincidentally true beliefs.
- OMO properties are suspiciously queer, akin to invisible and nonphysical gods. To illustrate the general idea behind the Argument from Queerness (AfQ), suppose someone claims there is an invisible unicorn floating above my head. This claim is possible, but not plausible. I would be justified in disbelieving in this unicorn. The unicorn is “queer” enough to be prima facia implausible, and we are prima facia justified in rejecting its existence. Moral oughtness is invisible, nonphysical, empirically detectable, and causally inert. To the Unbiased Atheist, moral oughtness likewise seems “queer,” giving her prima facia justification for disbelieving its existence.
- Evolution occasionally gives false beliefs (e.g. gods). So there’s precedent for evolution giving humans delusory intuitions for invisible nonphysical things.
- Moral oughtness beliefs have evolutionary value whether true or not. Moral oughtness beliefs potentially serve some evolutionary purpose: to get us to behave in the right ways.
- Our best theory for why we believe in moral oughtness doesn’t require its existence. We don’t need to posit something so extravagant as these invisible and highly metaphysical properties to explain moral beliefs; we can just say it’s a trick of evolution to get us to behave in certain ways.
Note: I do not think any single premise by itself is enough to justify the conclusion, but I do think the combination of all six premises justifies the conclusion.
Line (P3) is true by definition, since what I mean by Given atheism, moral oughtness probably doesn't exist just is Pr(not-M|A&K) is high. Line (P4) is supported by a mathematical theorem.
One of my key claims that the AftUA illustrates is that on atheism the objective evidence suggests that people’s intuitions of M are probably delusory. In some cases our justification for beliefs comes from non-evidential grounds. For example, consider for example the following brain-in-vat (BIV) hypothesis: you are recently created (say, within the past five years) brain in a vat hooked up to a supercomputer feeding you all the memories, sense experiences, and intuitions you know have. We can’t justify our belief that BIV is false based on evidence, because there can’t be any evidence against it. Instead it’s our intuition of its falsity that justifies our belief that BIV is false and that this perceived reality is real. The atheist moral objectivist (AMO) could similarly argue that he’s justified in believing OMO based on non-evidential intuition grounds, even if Pr(not-M|A&K) is high. But a crucial disanalogy is that in the case of BIV we don’t have any objective evidence suggesting BIV is true, whereas on atheism the objective evidence suggests that people’s intuitions of moral oughtness existing are probably delusory. This makes the a priori intuition option much less viable for the atheist.
SeekSecularism aims to undercut (P2) via his “Unbiased Observer” argument. (P2) says the Unbiased Atheist would be justified in believing Pr(not-M|A&K) is high. Showing that someone else would be justified in accepting A and M doesn’t attack the truth or justification for (P2).
The “Unbiased Observer” accepts moral oughtness because this observer has a subjectively experienced intuition of moral oughtness existing (namely, the “intrinsically motivating” facet of moral badness). Three problems:
- The Unbiased Atheist would not have this intuition, so this doesn’t affect the truth of (P2).
- X is morally bad is not admissible in K any more than X is morally wrong is since the conception of moral badness we’re using here has moral oughtness implicit in it.
- The Unbiased Observer argument fails to show that “this new observer can plausibility reason to both moral realism and atheism without tension” because it doesn’t address the tension I’ve argued for: the fact that given atheism, it seems that people’s intuitions of moral oughtness existing are probably delusory and not veridical.
For (2), I noted the variations of moral beliefs in human history (if raised in a different society, we might have had very different moral beliefs) and I noted that moral intuitions would likely track adaptive behavior (behavior conducive for survival and reproductive fitness) rather than truth. Evolution could even have evolved a species where adaptive behavior would be to kill one’s own sibling, and we know this because it’s already happened (the Nazca booby bird). All things considered then, in the absence of the supernatural, we would at best get coincidentally true intuitions of what these invisible and causally inert moral oughtness properties are really like rather than having genuine moral knowledge. The atheist could abandon naturalism in favor of us having some sort of supernatural clairvoyance of moral oughtness, but this seems far-fetched. This of course helps support the AfQ in premise (3); moral oughtness is so metaphysical it seems we’d need something like supernatural clairvoyance to know it exists.
Three reasons support (6): (a) the truth of premise (5); (b) Ockham’s razor suggests we not multiply our explanatory entities beyond necessity, and we already have an explanatory entity for our cognitive faculties in general (evolution gave us brains, brains give us intuitions, shaped further by the societal environment); (c) moral oughtness is causally inert; its presence or absence wouldn’t affect the evolutionary outcome.
SeekSecularism says, “Undermining the veridicality of rational intuitions which also constituted any explanations of them would be analogous to sawing the very branch from which one sits.” True, but irrelevant; the claim is not that atheism undermines all rational intuitions, but rather that on atheism the objective evidence is against the intuition of moral oughtness existing (the same does not necessarily hold for all intuitions).
The best SeekSecularism could appeal to on atheism for is the subjectively experienced intuition of moral oughtness existing, whether it’s directly via an intuition like M is true, or intuiting a proposition that has moral oughtness’s existence implicit in it, e.g. the intuition of a particular action being morally bad. The Unbiased Atheist would not have any such intuition (though she would not intuit any proposition that has M is false implicit in it either) and if the Unbiased Atheist is a good vantage point for evaluating the objective evidential relationship between A&K and M as I’ve argued, then (P1) is true.
The AftUA is also a good vantage point from which to evaluate where the objective evidence points on atheism. People can have conflicting subjective intuitions about whether moral oughtness exists, but if on atheism the objective evidence suggests that people’s intuitions of moral oughtness existing are probably delusory, this seems like a serious if not fatal problem for the AMO.
Moral oughtness is invisible, nonphysical, and empirically undetectable. So why shouldn’t the consistent atheist reject the existence of this invisible nonphysical thing that cannot be empirically detected, if the atheist is to reject the existence of invisible nonphysical deities that have not been empirically detected? Given atheism, it seems more likely that people’s belief in moral oughtness is a delusion brought about by evolution to get us to behave in certain ways and help our species survive. The AftUA helps show that given atheism, objective moral oughtness probably doesn’t exist, which in turn suggests that the first premise of the moral argument is probably true.