I've recently listened to the fascinating 80k Hours podcast (Sept 8, 2022) with Rob Wiblin and moral philosopher Andreas Mogensen (link here). From minutes 1:58:48 to 2:12:18 they discuss 'evolutionary debunking arguments', that we shouldn't trust our human moral intuitions as valid if they evolved to serve adaptive functions of survival and reproduction. (Adaptive value doesn't guarantee genuine ethical value.)

To an evolutionary psychologist like me, evolutionary debunking sounds very persuasive. I've taught some version of evo-debunking for decades, without knowing there was a moral philosophy literature on it. I haven't dived deep into that moral philosophy literature yet, but would be curious why the philosophers I've seen so far seem rather skeptical about evo-debunking -- especially since their understanding of evolutionary moral psychology often seems several decades out-of-date, and their arguments seem a couple of levels too abstract and general (e.g. not addressing specific human moral intuitions shaped by specific selection pressures, such as kin selection, sexual selection, group selection, predator-prey interactions, host-pathogen interactions, etc.).

I guess it's crucial for moral philosophy to defend itself against evo-debunking, insofar as most moral philosophy seems to be trying to articulate, systematize, and reconcile many different domain-specific human moral intuitions, and if those intuitions aren't credible guides to any legit ethics that rational beings would want to adopt, and if there's no good reason why they can be systematized and reconciled with each other across domains and situations, then the whole field of moral philosophy kind of falls apart.

Can anyone suggest some good writing by evo-debunkers who actually understand evo bio, evo psych, evo anthro, evo game theory, etc? Or by critics of evo-debunking with that level of understanding? I would love to learn more -- but I'm averse to overly general philosophizing about Darwinism that doesn't get into the nitty-gritty details of prehistoric selection pressures and the design details of human psychological adaptations.




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So I am a philosophy grad student with a shallow familiarity with this literature. The way I understand the people who object to the evo-debunking, they argue that the evolution stuff is a red herring---basically any causal story about the origins of our moral intuitions would do the same work in the argument, the empirical details don't matter. The real work is going on in the philosophical side of the argument, and that, they think, doesn't hold up. Might post again later with some paper recs.

Yep, this is just what I argue in 'Knowing What Matters' (summarized here).

The classic paper in the vein is probably Enoch's 'The Epistemological Challenge to Metanormative Realism: How Best to Understand It, and How to Cope with It.' (iirc, that's where he develops his famous "third factor" reply to causal debunking arguments.)

From the summarisation on the blog:

Either way, what matters is just whether there is a good justification to be found or not, which is a matter completely independent of us and how we originally came by the belief.  Parfit commits the genetic fallacy when he asserts that the causal origins "would cast grave doubt on the justifiability of these beliefs."

From personal experience, this seems to be a crux. Those such as Parfit, Geoffrey in the OP and me previously (sort of) think that this would be a counterargument against robust realism (e.g. premise 1 in my Post), whereas yourself, Vaughn, and most academic realist philosophers would agree with the counter.

What matters is just whether there is a good justification to be found or not, which is a matter completely independent of us and how we originally came by the belief.

This is a good expression of the crux.

For many people—including many philosophers—it seems odd to think that questions of justification have nothing to do with us and our origins.

This is why the question of "what are we doing, when we do philosophy?" is so important.

The pragmatist-naturalist perspective says something like:

We are clever beasts on an unremarkable planet orbiting an unremarkable star, etc. Over the long run, the patterns of thought we call justified are those which are adaptive (or are spandrels along for the ride).

To be clear: this perspective is compatible with having fruitful conversations about the norms of morality, scientific enquiry, and all the rest.

Vaughn - thanks for your reply. 

This is a very puzzling position. If the causal story about our moral intuitions identified plausible selection pressures that favored accurate, inclusive mental models of all other sentient beings as being morally worthy of consideration, then we'd have pretty good reasons to trust that our intuitions are roughly consistent with sentientist utilitarianism.

Whereas if the causal story identified selection pressures (such as kin selection) that favored over-weighting the well-being of our own kids relative to all other kids, then we'd have pretty good reasons not to trust the universalizability or impartiality of those intuitions, since they'd be designed to enact selfish-gene strategies. 

The details of the causal story seem to matter hugely -- just as they do in evolutionary epistemology (where we have very good reasons to expect that our mental models of nearby 3-D shapes in the external world are pretty accurate, whereas we don't have very good reasons to expect that our mental models of nation-scale economies are pretty accurate.)

Hi Geoff, Steve Stewart-Williams here. I wrote about evolutionary debunking arguments in my first book, Darwin, God and the Meaning of Life; see https://books.google.com.my/books?id=KBp69los_-oC&pg=PA290

All the best!


Oh hi Steve! Didn't know you were on EA Forum. I'll have a look at that. Thanks for sharing the link. Best wishes to you too.

EDAs are a problem for non-naturalistic moral realists in the British tradition (e.g. Sidgwick, Parfit). Some people think they're a problem for naturalistic moral realists too.

I've read ~10 philosophy papers that try to defend non-naturalistic moral realism against EDAs.

More than half of these defences have the following structure:

(P1) Metaethical claim about moral truth.

(P2) EDAs are incompatible with (P1).

(P3) Conclusion: EDAs are false.

A typical metaethical claim for (P1):

(P1*) The normative and the descriptive are fundamentally different (bangs table).

According to me, we should just accept EDAs and reject dubious versions of (P1).

Peter - yep, that's also my impression so far, that philosophers seem compelled to reject evo debunking arguments because EDAs would render much of moral philosophy's game (trying to systematize & reconcile moral intuitions) both incoherent and irrelevant. So they seem to be scrambling for ad hoc reasons to reject EDAs by any means necessary... and end up promoting spurious arguments.

But, I could be wrong, and there might be some more compelling, principled, and less reactive critiques of EDAs out there.

On the contrary, non-naturalistic moral realists such as Derek Parfit and Peter Singer note that evolutionary debunking arguments tend to strengthen (some forms of) non-natural moral realism. On an evolutionary account, external reasons for belief and action would seem to be redundant (pure impulse would suffice), yet Parfit and Singer argue for their existence.

Joshua Greene's book, Moral Tribes, presents a compelling EDA. He doesn't bother directly arguing against the philosophical objections to EDA.

In general I think Moral Tribes is a must-read for those who are interested in evolutionary psychology, moral philosophy and especially utilitarianism.

Among other things, Greene argues that utilitarianism needs a rebrand. His suggestion: deep pragmatism.

From Moral Tribes:

Deep pragmatism seeks common ground. Not where we think it ought to be, but where it actually is.

With a little perspective, we can reflect and reach agreements with our heads, despite the irreconcilable differences in our hearts.

We all want to be happy. None of us wants to suffer. And our concern for happiness and suffering lies behind nearly everything else that we value, though to see this requires some reflection.

We can take this kernel of personal value and turn it into a moral value by adding the essence of the Golden Rule: your happiness and your suffering matter no more, and no less, than anyone else’s.

Finally, we can turn this moral value into a moral system by running it through the outcome-optimizing apparatus of the human prefromal cortex. This yields a moral philosophy that no one loves but that everyone “gets”—a second moral language that members of all tribes can speak.

Deep pragmatism is utilitarianism in the spirit of Jeremy Bentham. Bentham is often misread as a narrow-minded moral realist. But he is best read as a political pragmatist: not seeking a metaphysical principle, but rather a practical principle—something most of us can agree on—upon which to build a stable polity.

Peter Singer authored A Darwinian Left so I’d say he at least has some understanding of the topics you mention. In a chapter of his book The Point of View of the Universe, co-authored with Katarzyna de Lazari Radek, he uses evolutionary debunking arguments to strengthen utilitarianism (from the perspective of a moral realist) and weaken other normative theories. They note that Darwin himself, in The Descent of Man, may have been the first to bring up the concept of an evolutionary debunking argument. I’m not whether it’s detailed enough to satisfy you, but it’s an interesting read nonetheless.

That all makes sense. It seems like most evolutionary debunkings would allow normative ethics to tilt more in a utilitarian direction, since our standard anti-utilitarian intuitions wouldn't carry as much rational weight.

I think there's a meta intuition here that non-utilitarian intuitions are evolutionarily biased but utilitarian intuitions are not (or less so).

While I share this intuition, I'm not sure it's logically coherent or justified. Like if a preference for helping neighbors can be debunked by EDA, what principled reason does someone have for favoring impartial altruism over partiality? It seems like one can just as easily argue that impartial altruism is an evolutionary spandrel that comes from kin altruism or reciprocity norms misfiring.

Sorry for the late response. I don’t actually think that non-utilitarian intuitions/principles are necessarily more evolutionarily biased than utilitarian principles. I think certain deontological precepts (like Kant’s categorical imperative) could also be less vulnerable to evolutionary debunking arguments than ‘common-sense’ moral intuitions, for example. I don’t think it’s as easy to argue that something like this, or the principle of Universal Benevolence, is the product of natural selection. It could be, but it seems we have less reason to think it is. And if ethics is about how we ought (in a reason-implying sense) to live, then focusing on what we have most reason to do is sufficient.

Once we’ve reasoned about “who counts?”, we can then move on to “what counts?”

I think hedonism is the most defensible answer to “what counts?”, and when you combine that with plausible answers to “who counts?”, you arrive at hedonistic utilitarianism.

Linch -- This is a fascinating issue, whether evolutionary debunking could affect utilitarian arguments as well as deontological arguments.

Once possible way this could work is that we could develop an evo-debunking account of why utilitarians value sentient experience over everything else. From our evolved brains' point of view, of course sentience seems like the whole point of the cosmos. But I could imagine an alternative ethics that values other kinds of phenomena, such as the complexity and functionality of all organic adaptations. I guess my earlier essay about 'body values' alludes to this -- our bodies may have moral interests that our sentience is not conscious of. 

Also, an evo-debunking of sentience-centric utilitarianism might value forms of computation, information processing, and intelligence that might not be 'conscious' in the human sense, but that might still be considered valuable from some perspectives.

Traditionalists and conservatives could also use an evo-debunking of individualistic sentience-centric utilitarianism to argue that certain cultural or aesthetic traditions, legacies, or achievements also have some kind of intrinsic moral value.

I find these metaethical debates really interesting (and important, though I know others disagree![1]), and I've tried to follow the debates and arguments long after I actually studied philosophy. I'm not an academic philosopher though, so I won't try to summarise the philosophical history of the literature or give a comprehensive reading list. Instead, I'll try to give an interested layman's outline

 *    *    *

I'll summarise[2] the general Evolutionary Debunking Argument (EDA) as the following:

  1. If evolution is true, then moral intuitions do not reliably track moral facts
  2. If moral intuitions do not reliably track moral facts, then we are not justified in believing any particular moral facts
  3. Evolution is true

And therefore, by a chain of logic, we conclude that:

C. We are not justified in believing any particular moral facts

The biggest disagreements here are, from my understanding, about premise 1. You could potentially also disagree with premise 2, though to me it seems most disagreements about it would more likely be disagreements about premise 1. I would be very surprised to see any respected moral philosopher try to attack premise 3! That's potentially why they don't get into the details of evolutionary psychology that you know so well, because it doesn't seem to affect the structure of the argument.

One common response is to say that you could deploy this argument against all human intuitive faculties, such as intuitions about our sense data, our social intuitions, even intuitions about mathematics, and so on. We can believe that these were generated by an evolutionary process, but nevertheless reliably track the truth of their content, so why should we think any differently about our moral intuitions?

Another  response is to point out that, logically, this argument doesn't prove that moral facts do not exist. This is true, but I find this incredibly unconvincing! If there's no causal way for a fact about the world to reach the human brain, saying "but it still could be true" seems like incredibly weak sauce to me, but as I'm not an academic philosopher I may not be doing that justice here.

The intuitionist defence (at least as far as I understand Huemer's intuitionism) is to say that our intuitive beliefs about moral facts are simply more strongly supported than any scepticism or debunking argument about moral facts and so we should reject the latter. This is akin to the Moorean switcheroo but applied to metaethics rather than external world scepticism.[3] 

The moral sceptic, I think, shouldn't be too convinced by these. Our moral intuitions are meant to track moral facts, but it doesn't seem that once we accept an evolutionary story for them that we have any reason to believe that there are such a thing as moral facts at all, rather than our moral intuitions about them. This is related to Harman's argument that Mogensen mentions in the podcast, and I must admit that this seems intuitively (ha) very strong to me. Though in the end, I'm not sure it really matters.[4]

  1. ^

    Nevertheless, the strength of Evolutionary Debunking Arguments (EDA) is also not just one that strikes at Effective Altruism but at all moral frameworks, including our critics and people who don't care about philosophy but just want to get on with their lives.

  2. ^

    This is just meant to be a summary, not publishable philosophy!

  3. ^

    Usually this kind of argument is paired with a non-naturalist moral realism that seems popular in academic philosophy, but I also find unconvincing, mainly due to Mackie's argument from queerness having a stronger intuitive pull for me than the non-naturalism of moral facts.

  4. ^

    If anyone can source this R. M. Hare quote for me then I'll offer to donate £50 toward a charity of your choice - everyone seems to cite 'Nothing Matters' in his book 'Applications of Moral Philosophy', but as far as I can tell it doesn't seem to be there. I find this upsetting, since it's a pretty close statement of my metaethical beliefs, but I can't seem to prove its accuracy.

JWS - thanks for this comment; it helps me get a little closer to understanding the anti-EDA position.

You mentioned 'you could deploy this argument against all human intuitive faculties'. Well, maybe. But I would draw a pretty strong distinction between evolutionary epistemology (including reasons why our perceptions and cognitions are under selection to be roughly accurate in some biologically relevant ways) versus evolutionary ethics (which can't really run the same kind of veridicality argument for why our moral intuitions should be accurate reflections of some external moral truth). 

Long story short, if an animal has the cognition 'this cliff is steep and I would die if I fell off it', there are pretty good reasons why evolution would nudge such cognitions to be accurate. But if an animal has the moral intuition 'my mate deserves punishment if she has sex with another male', there are pretty good reasons why evolution would favor that intuition, without that intuition carrying any truth-value beyond 'this intuition tends to promote paternity certainty and protects reproductive success'. 

Does "intuition" have a specific, carefully-guarded meaning in moral philosophy? Intuition as I understand it is vague. The term "intuition" captures examples of lots of opinions and preferences and conclusions that share the attribute of having a feeling or partial representation to the person holding them. For example, some moral intuitions could develop through or depend on personal experience but have this property of having a vague representation. For someone using my definition of "intuition", a discussion of whether all moral intuitions are evolutionarily-driven seems clearly wrong.

'Does "intuition" have a specific, carefully-guarded meaning in moral philosophy? '

Quite possibly not:  a bit over 15 years ago Timothy Williamson famously argued (in effect, that's not quite how he frames it)  that "intuition" as philosophers use it just isn't very well-defined: http://media.philosophy.ox.ac.uk/assets/pdf_file/0008/1313/intuit3.pdf   Rather, philosopher say "intuitively, P" when they can't be bothered arguing for "P" or "that's just an intuition, why would they be reliable" when someone says "P" and they disagree, but something about the terminology convinces people that we know what "intuitions" are in some substantive theoretical sense, when at most it just means something like a judgment that people in the current conversational context think feels "natural"', which, as Tim points out, actually covers pretty much any time a human being quickly and easily applies a word to something on the basis of pretty much any kind of evidence. 

David -- that makes sense to me; thanks for sharing the link to the Williamson paper.

I guess apart from 'evolutionary debunking' of intuitions, it's often possible to run some 'cultural/historical debunking' of philosophical intuitions, e.g. pointing out that our 'deepest intuitions' about particular issues have often changed -- often quite quickly -- over historical time periods, as culture changes.

Noah - 'intuition' does seem pretty vague.

I would expect evo-debunking arguments to be most relevant to 'moral intuitions' that are relatively universal across humans and cultures and historical epochs -- and there are many such intuitions studied by moral psychologists, evolutionary anthropologists, evo psych people, etc.

Whereas, 'moral intuitions' that are more culture-limited or idiosyncratic probably aren't as open to evo-debunking -- although they might be subject to other kinds of debunking (e.g. cultural/historical analysis of where the cultural 'intuition' originated; psychological analysis of how an individual's traumatic experiences shaped their moral judgments, etc.)

Well, I've been noodling that human physiology defines our senses, our senses limit our ability to represent information to ourselves, and correction for differences of sensory representation of different sets of information from the same class allows for better comparisons and other reasoning about each (for example, interpreting) . A classic example is television pharmaceutical drug ads. The ads present verbal information about the dangers of a medication in tandem with visual information showing happy people benefiting from the same medication. Typically.

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