Who’s Afraid of Disagreement about Disagreement?

ABSTRACT

This paper is not concerned with the (amply discussed) question as to the rational response to peer disagreement. Instead, it addresses a (considerably less often debated) problem to which many views about the (epistemic) significance of disagreement are vulnerable (to some extent or another): self-undermining. I reject several answers that have been proposed in the literature, defend one that has been offered (by meeting objections to it), and show that in its light, the prevalent assumption that the ‘equal-weight view’, a prominent view about disagreement, rationally requires us to suspend judgement about contentious matters, is seen to be too pessimistic.

KEYWORDS:

• Peer disagreement
• conciliationism
• self-undermining
• Right Reasons view
• scepticism

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Notes

1. I am using one of the several ways in which the term ‘epistemic peer’ is used in the literature. It applies to a person one (justifiably) takes to be as likely as oneself to get it right about the contested proposition. Pittard (2015), along with others, takes a peer to be a person ‘who seems as qualified as ourselves to assess the proposition’s plausibility’. Nothing hangs on the precise way the term is construed.

2. I follow Christensen (2007), Elga (2007) and Kelly (2010) in construing a disagreement as the adoption by two people of different credences (degrees of belief) with respect to some proposition. The alternative (Feldman, 2007; Kornblith, 2010; Sosa, 2010) is to discuss the issue in terms of the tripartite distinction: belief, disbelief and agnosticism. The probabilistic rendition is preferable. As Kelly (2010, 117) notes, when the disagreement is between someone who believes a proposition and someone who is agnostic about it, there is no possibility of implementing a compromise. And, similarly, there is – within this framework – no way of implementing a compromise for several other profiles of stances. And whether or not compromise is the correct response, it should at least be possible to implement.

3. Wedgwood (2007, ch. 11) argues that one is permitted (although not obliged) to have an ‘egocentric epistemic bias’, a modest bias towards one’s own beliefs. Perhaps no one holds the more extreme AS view, which Elga (2010, 176) aptly labels stubborn and uncompromising.

4. Kelly (2005) comes close to RR, but I do not count him as endorsing it. He concedes that (some) conciliation is required when there are many peers or superiors opposing one’s view.

5. The qualification needn’t concern us here. The cases in which EW does not require ‘splitting the difference’ are those in which one has ‘personal information’ that one’s disputant lacks, on the basis of which, one can justifiably believe that one’s reasoning is much more likely than one’s disputant to be right. I know I am not lying, drunk, short of sleep or high on drugs (Christensen 2007, 2011). We can suppose that our philosophical peers also satisfy these conditions, so EW does seem to require ‘splitting the difference’ with respect to it. The other kind of case is one in which the target proposition is (almost) self-evident, so that disbelieving it is (epistemically) beyond the pale: for instance, ‘1 + 1 = 2’. But views pertaining to disagreement, indeed philosophical views in general, aren’t of this type. Finally, the disagreement may be only apparent, verbal (Fumerton, 2010, 95). But again, the dispute concerning disagreement is not merely apparent. Graves (2013, 95, n. 8) discusses the difference between EW and ‘split the difference’ view more fully.

6. Proponents of EW include Christensen (2007), Elga (2007), Kornblith (2010) and Graves (2013).

7. Decker (2014, 1131) adduces another objection to Christensen’s ‘conflicting ideals view’. It enables the proponent of RR to adopt the mirror-image strategy, claiming that he endorses two ideals: respecting the evidence and respecting evidence about our epistemic error. When he remains steadfast in response to a disagreement, he is opting for the first ideal at the expense of the second.

8. The example is more perspicuous and its discussion less cumbersome if it involves a disagreement between a proponent of EW and someone he takes to be considerably superior to him epistemically. But nothing of substance hangs on this modification.

9. This might lead us to suppose that these are not concerned with epistemic justification. This suspicion will be based on Alston’s, Sugden, and Sherwood (1985, 59) conception of the ‘epistemic point of view’ as ‘defined by the aim at maximizing truth and minimizing falsity’. But I am granting for the sake of the argument Christensen’s supposition to the contrary.

10. There is, seemingly, another case that is problematic for Christensen’s (rational akrasia) strategy: a disagreement with a peer who holds a radical version of RR, and thinks the one who responded correctly should never conciliate. This is not a case in which rationality and accuracy diverge: RR is an evidentialist view. So it seems as if Christensen’s strategy won’t work in this case either. But I want to stay clear of such disputants, because it is not clear what RR prescribes for one who has responded incorrectly to the evidence.

11. It has been argued (Douven, 2009, Kelly, 2010) that permissive justification precludes conciliationism, or at least renders it unjustified. The thought is that the two disagreeing peers may have both adopted a rational attitude, so their disagreement does not provide evidence that they responded incorrectly to the evidence. If this line of reasoning were cogent, it would be incoherent for Pittard to offer a conciliatory suggestion pertaining to DAD that relied on permisivism. But I am persuaded by those (Christensen, 2009) who argue that even if justification is thought to be permissive, disagreement could still provide evidence of a mistaken response to the evidence. Since I do not wish to argue for this here, I merely note Pittard’s commitment to permisivism. Those who think it implausible (for reasons unconnected to conciliationism) will take that as a consideration against his proposal.

12. Decker (2014, 1120) argues that the mere possibility that a principle prescribes inconsistently (prescribes inconsistently in some non-actual situation) doesn’t impugn it. This is plausible for contingent rules, as attests Decker’s example. The father's injunction ‘Always do what your mother says’, which will engender incompatible prescriptions when the mother says, ‘Don’t do what your father says’, is perfectly acceptable in ordinary circumstances. But EW, which is an epistemic principle, is necessary, and applicable in every situation. But even if Decker is right, EW seems to prescribe inconsistently in the actual circumstances, because it is, as a matter of fact, disputed (among philosophical peers).

13. This proposal is reminiscent of solutions in game theory. An equilibrium point is a combination of players’ moves in which no player has an incentive to change his choice upon learning of the others’.

14. A stable credence, c, is one for which the following equality holds: c=c∙1/2+(1-c)∙1. The solution is c= ²/₃.

15. The restriction is required because even the proponent of RR will not suppose that we should be certain about all a priori truths, including those that we have never considered.

16. MacAskill et al. (2020) defend the more restricted claim, that we ought to be humble about the correct moral theory, assign significant degree of belief to views other than the one we favour. The reasons they adduce are that ‘ethics is hard’, and that we are liable to form our views in a biased manner (because of vested interests, for example). Our epistemological views are typically not affected by vested interests. Still, epistemology, too, is hard.

17. The difference between the initial and final values is x²/(x + 2). And in the relevant interval, [0,1] (x is a credence), it increases monotonically (its derivative is positive).

18. EW_new = 2∙EW_old/(2∙EW_old +2)=(2∙0.8)/(2∙0.8 + 2).

Additional information

Funding

The publication of this work was made possible with funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No [870883].