Sunday, November 8, 2015

Debate: Objective Morality Without God? (p. 3)

Home  >  Philosophy  >  Atheism/Theism

Preface



This is a debate between me and SeekSecularism over the truth of the first premise of the following moral argument:
  1. If God does not exist, then objective morality does not exist.
  2. Objective morality does exist.
  3. Therefore, God exists.
The debate so far:




Maverick Christian’s Rebuttal



Recap



With the following symbolization key:

M = Moral oughtness exists.[1]
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 stipulatively defined as an atheist with no intuitions of M being true and no intuitions of M being false such that prior to examining the data, her intuitions aren’t biased for or against the existence of moral oughtness (we can further explicitly state that prior to examining the data, she has no preconceived opinions about whether moral oughtness exists):

(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).

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.

General Remarks



In the early part of SeekSecularism’s opening statement, he argues that the atheist moral objectivist’s (AMO’s) intuition of objective moral oughtness (OMO) existing provides prima facia grounds for accepting OMO’s existence. I agree with this, but I have a few remarks.

SeekSecularism claims that OMO facts are logically necessary. An atheist moral nihilist (AMN) would disagree, and SeekSecularism offered no justification for this claim. I think (at least some) OMO facts are metaphysically necessary, but there doesn’t appear to be anything self-contradictory in their denials.

SeekSecularism claims that OMO facts are truths of reason. An AMN would disagree, and SeekSecularism offered no justification for this claim. It seems more plausible that our intuitions of OMO existing are just that: intuition, rather than reason per se. I would similarly balk at the idea that a theist’s intuitions of God’s existence constitute a “truth of reason.” That said, I think believing in God and OMO is reasonable, and that a priori intuition often provides prima facia justification for these claims.

SeekSecularism’s justification for the atheist accepting OMO relies on a priori intuition of its existence. Appealing to intuition of this sort is an appeal to a subjective experience rather than objective evidence. An atheist who is unsure whether the first premise of the moral argument is true might rightly ask why she should believe the moral realist’s intuition over that of the moral nihilist’s. So such justification via intuition has its limits.

AftUA: The First Premise



Atheists have differing intuitions of whether moral oughtness exists. Some atheists intuit its existence and some do not. The question, “How likely is it on atheism that people’s intuitions of moral oughtness existing are veridical?” can be symbolized as Pr(not-M|A&K), but what does K include and what can’t K include?

K obviously can’t include question-begging propositions like M is true or M is false since that would make Pr(not-M|A&K) trivial and we wouldn’t really be answering the question we’re asking, which is how likely M is in the first place on atheism. By the same token, K can’t include M is probably true or M is probably false. Thus, a priori knowledge (or alleged knowledge) like M is true or M is false would not be in K. Given all this and that our a priori intuition knowledge of moral oughtness existing would be excluded from K, basically the only type of a priori intuition knowledge allowed in K is the sort that the Unbiased Atheist might have (recall that prior to examining the data, the Unbiased Atheist has no intuitions for or against the truth of M). A posteriori knowledge is “publically shared” data and would be shared by AMOs and the Unbiased Atheist, and would include things like People have intuitions of moral oughtness existing.

SeekSecular balks 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?

Now let’s examine the four reasons SeekSecularism has for thinking that the Unbiased Atheist isn’t a good vantage point for Pr(not-M|A&K).
  1. SeekSecularism says the vantage point of the Unbiased Atheist is incompatible with the “Epistemic Thesis” in the sense that this vantage point excludes the a priori intuition of OMO existing. This seems irrelevant given what Pr(not-M|A&K) means. Remember, K can’t include any alleged a priori knowledge that OMO exists, just as it can’t include any alleged a priori knowledge that OMO does not exist.
  2. SeekSecularism says, “Any reason to be skeptical of moral intuitions would be reason to be skeptical of all rational intuitions,” and provides no justification for this claim. Suppose a theist claimed that “Any reason to be skeptical of my intuition that God exists would be reason to be skeptical of all rational intuitions.” An atheist might reply this isn’t true because while the objective evidence suggests that people’s intuitions of gods are delusory, the same does not go for all rational intuitions in general. Similarly, the AftUA suggests that while the objective evidence (on atheism) suggests that people’s intuitions of moral oughtness existing are delusory, the same does not go for all rational intuitions in general.
  3. SeekSecularism says, “My beliefs regarding evaluative facts are epistemically prior to my belief that God does not exist.” Maybe, but this seems irrelevant.
  4. SeekSecularism says, “My a priori knowledge of evaluative facts is not influenced by my a posteriori reasons for rejecting God’s existence.” Maybe, but this seems irrelevant.
All things considered, the Unbiased Atheist still appears to be a good vantage point for Pr(not-M|A&K), particularly given what K can and can’t include.

AftUA: The Second Premise



My support for (P2) was the following inductive argument (with each premise predicated with, “If atheism is true, this is true:”).
  1. There is zero empirical evidence for objective moral properties. This supports the idea that the Unbiased Atheist has no good reason to accept M.
  2. 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.
  3. OMO properties are suspiciously queer, akin to invisible and nonphysical gods.  Thus there’s at least prima facia justification for disbelieving moral oughtness’s existence.
  4. Evolution occasionally gives false beliefs (e.g. gods).  So there’s precedent for evolution giving humans delusory intuitions for invisible nonphysical things.
  5. 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.
  6. 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.
Therefore: (probably) premise (P2) is true.

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.

SeekSecularism never quite attacks this argument since his response is whether the AMO would be justified in accepting the conclusion, not the Unbiased Atheist, but I’ll comment on a few points.

Against premise (3) he says, “If it were supposed that some basic evaluative facts (known a priori) can only exist if they are like other kinds of facts (those known a posteriori) then it is clear that there probably aren’t any.” But the argument from queerness (AfQ) doesn’t say or imply that the queer entity needs to be non-queer to exist; it’s just saying that the queer entity is prima facia unlikely. To illustrate, consider the There is an invisible unicorn floating above my head claim. It’s strange in a way that makes it prima facia unlikely, but the claim could still conceivably be true and we could conceivably have evidence for it, e.g. if spray-painting above my head revealed a unicorn-shaped entity. So the AfQ can concede that maybe queer entity X exists and maybe we have evidence for X, but it’s still prima facia unlikely. The AMO could argue there is sufficient warrant to overwhelm this prima facia concern, but that wouldn’t contravene the claim of premise (3).

SeekSecularism claims premise (6) is unsupported. 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. All things considered, for our Unbiased Atheist the best theory for why we believe in moral oughtness doesn’t require its existence.

Where do we go from here?



In some cases our justification for beliefs comes from non-evidential grounds. 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.[2] Instead it’s our intuition of its falsity that justifies our belief that BIV is false and that this perceived reality is real. The 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.

Conclusion



The AMO and AMN can have different subjective intuitions about whether moral oughtness exists but the objective evidence favors AMN. If we exclude alleged a priori intuition knowledge of M in K (and to be fair, also exclude alleged a priori intuition knowledge of not-M in K) we see that Pr(not-M|A&K) is high, i.e. given atheism, moral oughtness probably doesn’t exist. The AftUA helps show this.

If the atheist accepts Pr(not-M|A&K) being high and concedes the moral argument’s first premise is probably true while also conceding the moral argument’s second premise, the atheist has little choice to but to accept atheism on faith. That would certainly be a strange concession—and a welcome one for the theist.


[1] SeekSecularism symbolized M as “objective moral oughtness” whereas my actual argument was “moral oughtness.” Still, “no moral oughtness” entails “no objective moral oughtness.”

[2] This can be shown with the help of mathematics (given that the sort of “evidence” we have in mind is something that makes a hypothesis more or less likely); see p. 2 of Why evidentialism sucks.

4 comments:

  1. Do you anywhere clearly, comprehensively define precisely what (objective) moral oughtness actually is?

    I've had a number of such discussions with atheists and others -- I think you may end up in an equivocation problem because both atheists and (conventional) monotheists will argue that some kind of objective morality is possible, but they each mean something very different by the phrase.

    ReplyDelete
    Replies
    1. Indeed! Please see my Redefining Morality article where I defined objective morality and describe moral oughtness and note how some atheists redefine morality. Basically though, objective moral oughtness is a supremely authoritative prescriptive ought (as I have defined this debate; it's the type of ought that does not have a purely descriptive meaning) regarding behavior, oughtness that exists independently of human belief and perception of it.

      Delete
  2. Very interesting blog, by the way. I enjoyed your concise intro to logic!

    ReplyDelete