Moral error theory, explanatory dispensability and the limits of guilt


Recently, companions in guilt strategies have garnered significant philosophical attention as a response to arguments for moral error theory, the view that there are no moral facts and that our moral beliefs are thus systematically mistaken. According to Cuneo (The normative web: an argument for moral realism, Oxford University Press, Oxford, 2007), Das (Philos Q 66:152–160, 2016; Australas J Philos 95(1):58–69, 2017), Rowland (J Ethics Soc Philos 7(1):1–24, 2012; Philos Q 66:161–171, 2016) and others, epistemic facts would be just as metaphysically problematic (or ‘guilty’) as moral facts. But since epistemic error theory is implausible, arguments for moral error theory prove too much and should be rejected. My aim is to argue that the success of this strategy is limited. In particular, the companions in guilt response fails against error-theoretic arguments motivated by concerns about explanatory dispensability, as recently developed by Joyce (The evolution of morality, MIT press, Bradford, 2005) and Olson (Moral error theory: history, critique, defence, Oxford University Press, Oxford, 2014: Ch. 7). To succeed, the response would require a prima facie plausible argument to the effect that epistemic facts are metaphysically dubious because they, too, are explanatorily dispensable. But, as I show, any such argument proves self-effacing: its premise commits us to believing in epistemic facts, while its conclusion forces us to deny their existence. Consequently, companions in guilt strategies don’t offer a panacea against arguments for moral error theory.

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  1. 1.

    See Garner (1990), Joyce (2001), Mackie (1977), Olson (2014) and Streumer (2017).

  2. 2.

    More precisely, most of the literature concerns categoricity and/or irreducibility. For simplicity’s sake, however, the exposition in the main text focuses on the former. We shall examine another feature, namely explanatory dispensability, in Sect. 3 and 4 below.

  3. 3.

    Since both moral error theorists and robust moral realists who advance companions in guilt responses subscribe to the conceptual claim, I shall take its truth for granted henceforth.

  4. 4.

    Jackson (1998) famously argues that, given plausible claims about supervenience, descriptive predicates and property identity, there are no irreducibly normative properties. For a full defence against most critics, see Streumer (2008).

  5. 5.

    My discussion focuses primarily on recent moral-epistemic companions in guilt arguments. See Bedke (2010), Cuneo (2007), Das (2016, 2017), Rowland (2012, 2016), Shafer-Landau (2003) and Stratton-Lake (2002). For discussion of moral-mathematical companions in guilt arguments, see Clarke-Doane (2014), and Fletcher (2018) for moral-prudential.

  6. 6.

    Henceforth, my discussion focuses—as is customary in the literature—on facts about epistemic reasons for belief, setting aside other kinds of epistemic facts (about, say, rationality, understanding or knowledge). Further, my discussion remains neutral with respect to the best account of what reasons are, as long as they are robustly normative (i.e. don’t reduce to, say, facts about probability, non-normatively construed).

  7. 7.

    In what follows, I shall take this way of motivating the Falsity Claim for granted. For criticism, however, see Olson (2014: Ch. 8). He argues that there are hypothetical as well as (what we might call) practice-dependent epistemic reasons for belief. Importantly, epistemic error theory doesn’t rule out those reasons. Thus, belief in epistemic error theory need not be self-defeating.

  8. 8.

    For another argument to the effect that the radical skepticism entailed by epistemic nihilism is implausible, see Rowland (2012: 13–15).

  9. 9.

    Cuneo (2007: 120f.) also notes a third implication of epistemic nihilism. If epistemic nihilism were true, there couldn’t be any arguments for anything. This is because the premises of non-question-begging arguments offer evidential support (and thus articulate epistemic reasons) for the conclusion. But if there are no epistemic reasons, we couldn’t have any evidential support and thus arguments.

  10. 10.

    Consider, for example, the recent exchange between companions in guilt theorists such as Rowland (2012, 2016) or Das (2016, 2017) and moral error theorists such as Cowie (2014, 2016)—during which, in my estimation, the former keep the upper hand. For more on Cowie’s objections and how they differ from mine, see fn. 30 below.

  11. 11.

    See Barnes (2000) for more on this anti-superfluity version of Ockham’s razor. See Mogensen (2014: Ch. 4) for criticism of the application of Ockham’s razor in the context of evolutionary explanations of morality.

  12. 12.

    Strictly speaking, these premises don’t quite establish the conclusion that we should believe that moral facts don’t exist. Rather, as Joyce (2005: 184f.) concedes, that only follows if it can also be shown that moral facts are irreducible to natural facts. However, as mentioned in fn. 3, I shall take the truth of the conceptual claim for granted. According to that claim, moral discourse presupposes moral facts with feature F, where F concerns categoricity and/or irreducibility. I am grateful to an anonymous referee for pressing me on this point.

  13. 13.

    I am grateful to an anonymous referee for forcing me to think more carefully about the relationship between (3) and moral error theory.

  14. 14.

    See, e.g., Shah (2003).

  15. 15.

    See, e.g., Williamson (2000).

  16. 16.

    Of course, if justification is factive (e.g. Sutton (2007)), it follows straightforwardly that, if you should believe p, p is true.

  17. 17.

    See, e.g., Lehrer (1990: Ch. 8).

  18. 18.

    This is, of course, by no means the final word. Rather, it is a matter of active debate how exactly explanatory dispensability (or evolutionary debunking) arguments relate to moral error theory. For further discussion, see Joyce (forthcoming) and Olson (2019).

  19. 19.

    Of course, one might think that epistemic skepticism, unlike epistemic error theory, is just blatantly incoherent: it tells us that we are epistemically obliged to deny the existence of epistemic obligations! If that is correct, the dilemma to follow in the main text won’t be required to bring out the implausibility of the view and motivate the corresponding Falsity Claim. Further, if that is correct, epistemic skepticism might be even more unattractive than epistemic error theory, for the latter isn’t blatantly incoherent.

  20. 20.

    Assuming that this isn’t just blatantly incoherent anyway. See fn. 19 above.

  21. 21.

    I say merely ‘inspired’ because Street is an epistemic constructivist, not error theorist. So, she doesn’t take her argument to establish that there are no epistemic facts whatsoever. Rather, she takes it to establish that robust or mind-independent epistemic facts are dispensable to evolutionary explanations of epistemic beliefs—which is perfectly compatible with the existence of mind-dependent epistemic facts. But this wrinkle doesn’t matter for our purposes. After all, both the error theorist and the robust moral realist deploying a companions in guilt strategy reject such mind-dependent normative facts as misrepresenting the nature of our normative concepts. (In other words, they both subscribe to the conceptual claim that moral discourse presupposes the existence of moral facts with feature F.) For both of them then, Street’s argument would thus establish that there are no epistemic facts simpliciter.

  22. 22.

    Or, at least, not to robust or mind-independent epistemic facts. See fn. 21 above.

  23. 23.

    The reason is dialectical: the aim of the companions in guilt strategy is to respond to the explanatory dispensability argument by drawing an analogy to epistemic facts and arguing that we have good reason to believe in their existence. But drawing that analogy only works if epistemic facts are subject to the same threat as moral facts, i.e. if their explanatory dispensability is metaphysically problematic.

  24. 24.

    Why think that a merely prima facie plausible argument suffices for that? Because a methodological view on which an argument needs to succeed outright to render a class of entities problematic seems too demanding to be plausible. After all, very few (skeptical) philosophical arguments ultimately succeed. Yet, most of us still think that those arguments raise a challenge worth engaging with.

  25. 25.

    The explanatory dispensability of a class of facts doesn’t strike me as brutely problematic. Rather, it only becomes problematic once we combine it with a methodological principle such as Ockham’s razor. Doing that, though, amounts to putting forth an argument.

  26. 26.

    Woods (2016) avoids talk of dispensability and cashes out self-effacement more simply in terms of undermining justification (instead of impugning rationality, as I do below). He also raises his worry for a slightly more complex, namely burden-shifting, abductive argument. According to this argument, epistemic realists ought not continue holding their epistemic beliefs—unless they have additional, non-abductive reasons for doing so. However, I take it that his point carries over neatly to the argument discussed in the main text. After all, it boils down to the claim ‘…that some arguments against mathematical, logical and evaluatively normative [i.e. epistemic] beliefs presuppose their truth, so we cannot coherently doubt them by such methods’ (2016: 66). See also Rinard (forthcoming) for a self-effacement argument against external world skepticism.

  27. 27.

    For more on the epistemic formulation of Ockham’s razor, see Baker (2008).

  28. 28.

    Most of the literature on epistemic akrasia focuses on intuitively abominable conjunctions such as ‘P, but I shouldn’t believe that P’. But, if anything, ‘P, but I should believe not-P’ is even worse in that regard. Further, the latter is entailed by the former, assuming the overwhelmingly plausible principle that if you should believe not-p, you shouldn’t believe that p. (That principle, in turn, flows from a more general rational requirement not to believe contradictory contents). For an extended argument that epistemic akrasia is irrational, see Horowitz (2014).

  29. 29.

    Is this kind of flaw plausibly called ‘self-effacement’? Ultimately, that doesn’t matter. Rather, it only matters that the above argument exhibits this flaw and thus isn’t prima facie plausible, while the analogous argument against moral facts doesn’t share this flaw and is prima facie plausible as a result. That alone is enough to undermine the Parity Claim, as I explain in the next paragraph of the main text.

  30. 30.

    Note that my self-effacement worry is distinct and more forceful than Cowie’s (2014) recent attack on the Parity Claim. He argues that the Parity Claim stands in tension with the Falsity Claim. In more detail, he thinks that, unlike epistemic error theory, moral error theory isn’t plausibly self-defeating: ‘…the moral error theory would have the consequence that there are no moral reasons… But it would not have the consequence that there are no epistemic reasons’ (411). But that undermines the Parity Claim: ‘[i]t undermines the parity premise because it entails that there is a sufficient reason for rejecting the epistemic error theory (namely, that it is self-defeating), that is not also a sufficient reason for rejecting the moral error theory.’ (ibid.) Now, importantly, my worry is distinct, for it has nothing to do with the Falsity Claim, focusing instead on whether explanatory dispensability is metaphysically problematic for epistemic facts—and what that means for the Parity Claim. Further, my worry is also more forceful: unlike Cowie’s, it doesn’t mischaracterize our joint target, namely the Parity Claim. Cowie takes two classes of facts to be on a par (for the purposes of a companions in guilt strategy) only if they share both a metaphysically problematic feature F (such as, say, categoricity) and the grounds for believing that that given class of facts exists (namely self-defeat, in his case). But that is dialectically inappropriate, as Das (2016) and Rowland (2016) have been quick to point out. After all, moral error theory questions the existence of moral facts based on a putatively metaphysically problematic feature F (such as categoricity). In turn, the aim of a companions in guilt response is to show that another class of facts shares F (i.e. the Parity Claim), but that an error theory about those facts would be false (i.e. the Falsity Claim). So, the correct sense of moral-epistemic parity only involves the shared metaphysically problematic feature F, not also the grounds for believing that a given class of facts exists. Since my worry invokes exactly that sense, focusing on moral-epistemic parity strictly in terms of explanatory dispensability, it proves more forceful than Cowie’s.

  31. 31.

    For more on such ‘normatively reducible’ or—as I call them—non-genuine epistemic facts, see also Olson (2014: Ch. 8).

  32. 32.

    I am grateful to an anonymous referee for raising an issue along these lines.

  33. 33.

    I am grateful to an anonymous referee for raising this worry.

  34. 34.

    See, for example, Baker (2008), Barnes (2000) or Schaffer (2015).

  35. 35.

    For discussion, see Clarke-Doane (2014), McGrath (2014) and Scanlon (2014: Ch. 2).

  36. 36.

    See Woods (2016: 58–60).

  37. 37.

    See Mogensen (2015, 2016).

  38. 38.

    See Enoch (2011) and McPherson and Plunkett (2015) for criticism.


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I am grateful to Chris Blake-Turner, James Brown, Matthew Chrisman, Chris Cowie, Guy Fletcher, Giada Fratantonio, Francois Jaquet, Felix Pinkert, Geoff Sayre-McCord, Kieran Setiya, Mattias Skipper and Mike Ridge for helpful feedback on previous drafts of this paper. This paper was written while holding a Doc.Mobility Fellowship of the Swiss National Science Foundation and a thesis completion award of the Janggen-Poehn Foundation.

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Wittwer, S. Moral error theory, explanatory dispensability and the limits of guilt. Philos Stud 177, 2969–2983 (2020).

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  • Moral error theory
  • Companions in guilt
  • Epistemic reasons
  • Explanatory dispensability
  • Evolutionary debunking