Disagreement elimination strategies

Here is a sample of methods for addressing disagreements. I doubt that they exhaust the solution space, but they are certainly the highest mountains in the range. I will discuss them in order of most intuitively plausible to most controversial. It is only by placing relativism on the map of disagreement solutions that we will be able to evaluate its merits and demerits, and when, if ever, it is the optimal choice.

Keep arguing until someone capitulates. Continued argument is the default mode, not just in epistemology, but in the quotidian affairs of life. From routine, everyday matters to subtle disputes in technical fields, continued debate until widespread consensus is reached is the common course of action. For philosophers who assume there is an absolute truth that we can ferret out through universally recognizable reason, it is easy to see the appeal of the relentless argument approach. And surely this is what we ought to do in most cases. If you and I disagree about whether a Ford Focus is cheaper than a Toyota Impreza, whether Saturday is the 24^th or the 25^th, and whether we need to buy milk, we should obviously search out the evidence that settles the matter. Even if we disagree about the Copenhagen vs. the Everett-Wheeler interpretation of quantum mechanics, or the linguistic taxonomy of Hindustani, or whether the demise of feudalism was a cause of the Industrial Revolution, continued debate and evidence-gathering seems like the right approach.

Compromise. Other times it seems that two parties have dug in their heels to an extent that each might despair of ever bringing their opponent around to their point of view. In such cases it may not be clear what kind of evidence would definitively decide the issue for one side or the other. When that happens, compromise starts to look attractive. For example, an abortion conservative (who believes that all abortions, even of zygotes, is morally impermissible) and an abortion liberal (who believes that all abortions, even of very late-term foetuses, is morally permissible) might settle their differences through compromise on a moderate position. Perhaps they decide that early abortions are morally permissible, late abortions are not, and that they can amicably work out the middle-term boundary cases. In metaphysics, endurantists and perdurantists sometimes attempt to compromise by distinguishing between objects and events. Objects are then said to endure through time whereas events perdure and have temporal parts.

Compromise is a bit more contentious than fighting until capitulation, and it may not appeal to someone antecedently convinced that they are in possession of the complete truth on a topic. For example, suppose my brother and I disagree on how to fairly divvy up an apple pie. I want to split the pie evenly so we each get half. My brother wants the whole thing for himself. Compromise would suggest that we split our differences so that I get ¼ of the pie and my brother gets ¾. Surely in this case I should stick to my guns and keep arguing until he capitulates.

Ambiguity. A dispute may seem intractable because the two parties are talking past each other and using their words with different meanings. Once the disputants work out their linguistic differences and settle on a common usage, they can reach agreement. The most familiar example is fixed ambiguity. William James opens his lecture What Pragmatism Means with a famous example of settling a dispute through disambiguation.

Once James was able to make clear two different senses of ‘to go round’, there was no longer any dispute to be had. James offered the squirrel story as an example of his pragmatic approach to ‘settling metaphysical disputes that otherwise might be interminable’. Subsequent philosophers have occasionally signed on for the Jamesian strategy. Max Kölbel, for example, argues that the predicate ‘is true’ is ambiguous between a deflationary sense and a substantial sense, and while these two different senses are systematically related, neither deflationism nor a more robust treatment of the truth predicate is the uniquely correct theory of truth.Footnote ² Ernest Sosa argues that ‘knowledge’ is ambiguous between animal knowledge and reflective knowledge. Animal knowledge is externalist, true belief formed according to some reliable cognitive virtue. Reflective knowledge is internalist, and adds the dispositional ability to reflect upon and defend the reliability of one's sources.Footnote ³ In this manner Sosa employs an ambiguity solution to settle the internalist/externalist debate in epistemology.

A second philosophically current form of an ambiguity solution is contextualism. According to contextualism, the meaning of a term fluctuates between or among different senses, depending on features such as conversational context, standards of utterance, and so on. In the case of epistemic contextualism, the truth conditions of sentences that ascribe knowledge vary by context, and different propositions are expressed in different contexts. For example, in DeRose-style contextualism there are contexts in which the standards for knowing are very high, in which case ‘Sam knows that the bank is open on Saturday mornings’ is false, and contexts in which the standards are lower, so that ‘Sam knows that the bank is open on Saturday mornings’ is true. Contextualism thereby uses an ambiguity solution to settle epistemic disagreements, e.g. over scepticism. Sceptics think that there is no empirical knowledge, and non-skeptics disagree; contextualism allows them both to be right. In a context where sceptical possibilities are salient options and standards for knowing are maximally high, then no one has empirical knowledge. In non-skeptical contexts where sceptical possibilities are, for whatever reason, not salient options and the standards for knowing are lower, then one does have empirical knowledge, even when the evidence base is the same in both cases.

Not everyone is satisfied with ambiguity solutions to disagreements. James himself noted that his solution to the squirrel problem did not make everyone a happy camper: ‘one or two of the hotter disputants called my speech a shuffling evasion, saying they wanted no quibbling or scholastic hair-splitting, but… just plain honest English’. John MacFarlane notes that many object to contextualism on similar grounds. Contextualism solves disputes by showing that there never was a true disagreement at all; according to the detractors, this fails to respect the intuition that any adequate solution to disagreement ought to allow that there really was a dispute to start with.Footnote ⁴ Therefore contextualism is not a satisfactory solution. MacFarlane's rejoinder is to give fine-grained distinctions among different types of disagreements, thereby making the case that ‘disagreement’ is ambiguous. As a result of this ambiguity, he concludes that it is ‘merely terminological’ which disagreements are genuine. Unfortunately, MacFarlane begs the question against the critics of contextualism, since their very objection is that ambiguity strategies, including contextualism, miss the point of disagreement. James's campers who rejected his ambiguity solution were not going to be soothed if told that their objections were grounded in yet a further verbal dispute.

Pyrrhonian skepticism. When arguments have gone on a long time without any realistic prospect of resolution, neither party is willing to compromise, and neither finds an appeal to ambiguity or contextualism satisfying, then they may decide to agree to disagree. Agreeing to disagree solves a dispute by giving up the fight, and has a respectable philosophical pedigree in the Pyrrhonian scepticism of Sextus Empiricus. The Pyrrhonian skeptic aims for peace of mind (ataraxia) through the suspension of judgment (epochē). According to Sextus, the Dogmatic philosopher claims to have discovered the truth and in opposition the Academic philosopher denies that the truth can be apprehended.Footnote ⁵ The Pyrrhonian skeptic takes a third path, Sextus's ‘Skeptic Way’ by suspending judgment without hope of leaving the state of suspension. As Mates puts it, ‘the characteristic attitude of the Pyrrhonist is one of aporia, of being at a loss, puzzled, stumped, stymied’.Footnote ⁶ Contrary claims are regarded as equally credible or discredible, and the skeptic is content to report only appearances, or how things seem to her. More accurately, the skeptic holds even the contention of equal credibility as tentative, and as just how matters presently appear. Really, the skeptic has no idea what to believe, and so removes from the fray altogether.

Sextus writes that one of the ‘modes of epochē’ is ‘based on disagreement… we find that both in ordinary life and among philosophers, with regard to a given topic there has been reached an unresolvable impasse on account of which we are unable to reach a verdict one way or the other, and we end up with a suspension of judgment’ (Sextus 1.165 in (Ibid.)). Sextus rejects any distinction between a dispute that cannot be reconciled, and one that the disputants cannot reconcile. He determined that all disagreements are irreconcilable, if ‘reconciliation’ means that it can be rationally decided which party is right and which wrong. It is the Skeptic Way to suspend judgment about all propositions (even, officially, this one). All forms of scepticism are notoriously difficult to put to bed, and Pyrrhonism is no exception. While one might reasonably conclude that as a general solution to the problem of disagreement Pyrrhonism is chasing a flea with a sledgehammer, it is still quite possible that Pyrrhonism is a plausible approach to local disagreements.

Relativism. Relativists resolve disagreements by declaring that everyone is a winner.Footnote ⁷ Consider Hilary Putnam's familiar example regarding unrestricted mereological composition (UMC). Suppose you have three marbles. How many things do you have? If one accepts unrestricted composition, then the answer is ‘seven’. If one rejects it, then the answer might be ‘three’. How many things there are is thus relative to which composition principle is correct. As it stands, that's rather innocuous. However, it is very hard to determine which composition principle is correct, or even that any composition principle is correct. David Lewis argued that a satisfactory composition principle must accommodate our intuitions about which ostensible things are genuine objects and which not.Footnote ⁸ Such a principle would give a precise ruling in every case, for instance, that a marble is an object but a pair of marbles is not. However, our intuitions about objects involve vagueness, as the sorites paradox shows. Thus no composition principle could accord with our intuitions. Lewis takes this argument to motivate unrestricted composition, but one might reasonably conclude instead that there is no uniquely true principle of mereological composition, and that it is theoretically arbitrary which we choose. If that's right, then the nature of objects is deeply relative – in the case of the marbles, it is true that there are only three things (relative to a more atomistic mereology) and it is also true that there are seven things (relative to a mereology with unrestricted composition).

Where does this leave disagreement? Some, like Carol Rovane and Paul Boghossian, think that the relativist solution is no different from ambiguity when it comes to preserving the idea that there is a genuine disagreement.Footnote ⁹ Consider our mereological example. The UMC person believes the following is true. p: three marbles compose seven objects. The mereological atomism (MA) person believes that p is false. The peacemaking relativist comes along, rules that no composition principle is absolutely true, and concludes that q: from the perspective of UMC, p is true, and from the perspective of MA, p is false. Both the UMC and the MA partisans agree on q. Therefore, there is no longer any disagreement between them; in some sense, there never really was a disagreement. Relativism's a thesis about truth, and so it was always the case that p is true in UMC but false in MA. The putative disagreement originally arose because of an inadequate state of knowledge regarding the truth conditions of The UMC and MA persons never really had a conflict over the truth of p, rather they had a superficial epistemic disagreement.

There are two reasons that the Rovane/Boghossian argument is unsuccessful. The first reason is that someone adopting the perspective of UMC will rightly find any reasons given for not-p completely unconvincing, and the person in perspective MA will properly find the reasons provided for p completely unpersuasive. Such a state of affairs looks mightily like a disagreement. As MacFarlane puts it,

Under relativism, the disagreement is to be located more broadly at the clash of perspectives.

The second reason that the relativism-means-no-disagreement argument fails is that all approaches to settling disagreements (with perhaps the exception of Pyrrhonism) aim at resolution. Consider compromise. If two metaphysicians who disagree about persistence compromise and decide that events perdure and objects endure, then they no longer disagree with each other. Surely it would be a mistake subsequently to accuse the compromisers of failing to preserve their disagreement. They compromised precisely to get rid of their disagreement. Complaining that after compromise there is no longer a dispute is a case of wanting to have one's cake and eat it too.

Rovane and Boghossian might rejoin that relativism is different from compromise in that if relativism is true, then the original disputants never did really disagree with each other. They simply failed to recognize that their respective claims were merely relatively true. The compromisers, on the other hand, at least once did disagree with each other (prior to compromise).

The trouble with such a rejoinder is that if one is both a truth absolutist and promoting compromise to settle a disagreement, then one must hold that the disagreeing parties never really had a truth conflict at all; right from the start each was partly right and also partly wrong. Compromising is an epistemic strategy by which they came to recognize that fact. As with the relativist solution, the compromisers' original disagreement was also due to inadequate knowledge. All disagreements are epistemic in nature and the different approaches to solving them simply exploit different ways in which we can go wrong. Pointing out that a dispute is the result of one or more of the disputants failing to understand the truth conditions for p, or committing some similar epistemic error, is insufficient to show that there is no true disagreement.

Ambiguity solutions dissolve disagreements by showing that there is no one proposition about which the disputants disagree, which is why there is a clear sense in which their dispute was a faux disagreement. The continued argument, compromise, and relativist solutions all acknowledge that the disputants disagree about the same proposition; they just locate the source of the disagreement in different places. All of the canvassed approaches, except Pyrrhonism, allow for the possibility of knowledge. Compromise and ambiguity allow that each disputant has a part of the truth; continued argument and Pyrrhonism do not, and only ambiguity allows that each disputant is completely right. Here is a plot of the various solutions to disagreement, and their commitments.

Given that we have a variety of options for addressing disagreements, when should we vote for relativism as the best solution? One answer is that relativism secures our allegiance when it is the most intuitively plausible of the options, given what each entails on the chart above. Of course, intuitions vary here, and it might be all too easy to convert one person's ponens into another's tollens. Perhaps a more promising idea is that there are certain kinds of disagreements to which continued argument, compromise, ambiguity, and Pyrrhonism give especially unappealing answers. The best place to look is at disagreements that in some manner seem epistemically irresolvable; otherwise continued argument is presumably the default approach.

Three kinds of epistemic irresolvability

We'll never have enough evidence. One sort of epistemic irresolvability is when we can get the right kind of evidence to settle a dispute in favour of one side or the other, but we will never be in a position to tip the balance. For example, consider the proposition ‘the number of stars in the universe is even’. The probability that humanity will ever be able to answer the question of the number of stars with sufficient accuracy to answer the odd vs. even question is essentially zero. A battle between the oddists and the evenists is therefore evidentially irresolvable. Continued argument seems rather pointless in this example, since both parties know going in that sufficient evidence is forever past the horizon. There's no compromise position between odd and even, and there is not much an ambiguity solution could do given the state of evidence. Perhaps if we had a complete inventory of the universe there might be vagueness-driven ambiguity over what counts as a star, and that would bear on the odd vs. even question. But that state of affairs is at great epistemic distance. Pyrrhonism, however, looks like the right approach here – we should just suspend judgment about whether the number of stars is even or odd. In fact, we should probably suspend judgment indefinitely, without hope of resolution, just as Sextus recommends. There's no motivation for relativism here.

We'll never have the right kind of evidence. Another sort of case is one in which we are not in a position to get the right kind of evidence. Epistemological mysterians about the mental, such as Colin McGinn, defend exactly this view.Footnote ¹¹ The mysterians argue that minds are limited along different dimensions and so are cognitively closed to certain aspects of the world. No canine will ever plumb the depths of calculus, and in this manner dogs are cognitively closed to solving differential equations. The mysterians maintain that is it nothing but egocentric prejudice to suppose that human beings are unlike dogs and that we somehow are exempt from cognitive closure and can reason our way to everything knowable. In particular, mysterians maintain that the problem of consciousness is epistemically irresolvable. McGinn argues that our access to the nature of consciousness is only through introspection (but introspection tells us nothing about the brain), and our access to the nature of the brain is only through sense perception (but perception tells us nothing about consciousness). Therefore we have no epistemic means to grasp the connection between the brain and consciousness.

Part of the mysterian point is that continued argument is hopeless; we'll never crack the mind-body nut. If the mysterians are right and we have no cognitive access to the right sort of evidence to explain the relationship between consciousness and the natural world, then it is hard to see how the options of compromise or ambiguity could come into play. Compromise between what and what? What are the terms that we could disambiguate if mysterianism is correct? As in the case of simply not having enough evidence, the case of not being able to get any of the right kind of evidence also seems to mitigate for Pyrrhonism. If the mind-body nexus is eternally inaccessible to us, we should suspend judgment about it forever, without hope of solution. Again, relativism does not seem like a plausible option in this case.

There's no such thing as the right kind of evidence. A third example of epistemic irresolvability is when there is no such thing as the right sort of evidence. Now, I believe, we are homing in on the relativist's domain. As Crispin Wright puts it, ‘disputes are potentially irresolvable, we think, not because the facts in question can transcend our impressions, but because the impressions themselves are in some way basic and constitutive; so when they conflict, there need be no further court of appeal’. Wright is quite right to write that proper irreconcilable differences are to be located in basic evidence, although I believe that the case he provides as an example is unsuccessful. Wright's paradigm example of an irreconcilable difference involves predicates of personal taste, a defense of de gustibus non est disputandum. He offers a dispute over the deliciousness of rhubarb as a paradigm example of an intractable disagreement where neither party is mistaken or otherwise at fault.Footnote ¹²

Max Kölbel concurs, writing, ‘most people think that there can be faultless disagreements at least on some topics… the examples I will be using will mostly concern matters of taste because I believe the intuition that faultless disagreement is possible is strongest in this area’.Footnote ¹³ Both Kölbel and Wright take such examples as motivators of relativism, and both dismiss other approaches to settling taste disagreements as seriously mistaken. The approach of keep arguing until capitulation presumes that if two people disagree about the deliciousness of rhubarb, then one person is just plain mistaken; there is some objective fact of the matter as to whether it is delicious that the faulty person either fails to appreciate or is unable to appreciate. Wright suspects this view of ‘semantical and metaphysical superstition’.Footnote ¹⁴ Kölbel rejects the continued argument solution because it fails to give an error theory – the assumption of objective truths about taste doesn't explain the Platonic intuition that matters of taste are more subjective than disagreements about numerosity, size, or weight.Footnote ¹⁵

Wright and Kölbel may be right. However, I do not think that their arguments dig down to the bedrock of the irreconcilable differences that are needed to sufficiently motivate relativism. Or, to choose a tennis metaphor, they haven't hit the put-away shot. The reason is that the taste absolutist still has a couple of decent ways to put the keep arguing until capitulation solution to disagreement back in play. As long as the absolutist is still on the court, relativism is not the obvious winner.

Response one: proper functioning. Sometimes the Latin expression above is rendered de gustibus et coloribus non est disputandum. There is no disputing about tastes and colors. But, of course, there is perfectly reasonable disputing about colors; we consider that some people are colorblind. That is, they are cognitively deficient and unable to accurately perceive the genuine colors of objects. People with cone monochromacy are unable to perceive any chromatic hues at all, those with protanopia or deuteranopia are unable to distinguish between red and green, and tritanopes cannot see a difference between blue and yellow. One might argue, as does Hardin and others, that there are no true colors at all, and that there are sophisticated philosophical reasons to accept color subjectivism. In that case, no one perceives the genuine colors of objects as there are no genuine colors. Of course, even if color subjectivism is right, there is still a difference between color normals and the colorblinds. The former possess a cognitive ability of discrimination and judgment that the latter lack. One possibility is that in matters of taste that one person is simply cognitively or perceptually deficient and is unable to perceive rhubarb like a taste-normal. If the person weren't impaired in this way, then their views about the deliciousness of rhubarb would conform to the norm (at least to the extent that color normals agree about properties like saturation, intensity, and hue).

The taste relativist might rejoin that an inability to taste the flavor components of rhubarb is one thing, but normative judgments are something else altogether. Two people might be taste-normal, that is, capable of sensing all the flavor components, but still completely disagree about whether rhubarb is delicious. Such a rejoinder is not terribly compelling; the assumed counterfactual might well be false, and in any case is an empirical matter. Perhaps the vast majority of taste-normals do agree about the normative qualities of tastes.

MacFarlane quickly dismisses the possibility that taste is objective, and thinks that the analogy above to colorblindness is inapt because colorblind people show humility in their color judgments and disputants about taste do not. ‘We do not seem to regard the fact that many others disagree with us as grounds for caution in calling foods delicious’, he writes.Footnote ¹⁶ Even if MacFarlane is right, epistemic hubris is no evidence that there are not aesthetic universals to which a taste objectivist can appeal. It may just take a bit of psychological sleuthing to uncover them; nature is subtle. For example, only recent research has uncovered cross-cultural empirical evidence that people find faces more attractive if the faces are average, bilaterally symmetrical, and sexually dimorphic.Footnote ¹⁷ While it is a chestnut to hold that beauty is in the eye of the beholder and is personally or culturally relative, if we're hard-wired to perceive some people as more attractive than others, that fact diminishes the appeal of beauty relativism.

Most facial beauty researchers argue that facial characteristics flag mate quality, with attractive faces indicating sexual maturity, high reproductive potential, low parasite load, good nutrition, minimal inbreeding, lack of retardation, and so on.Footnote ¹⁸ It is easy to see how evolution would build in detectors for health and the fitness of potential mates and have beauty be the marker, just as pain is the evolution-built marker for injury. Similarly with tastes it is likely that deliciousness is the indicator for nutritious and non-poisonous food. If someone finds amanita phalloides particularly scrumptious, we might reasonably think there is something seriously wrong with their taste cognition. Besides facing an immediate practical problem, a lover of death cap mushrooms is not a properly constituted and functioning human being. Put another way, the adoption of a proper functioning account of normative taste properties allows for continued argument about who has accurate judgments of taste and who does not.

A proper functioning story may be wrong, or perhaps there really are no descriptive universals about taste to underwrite a proper functioning account of taste normativity (although that is hard to imagine – we might find a remote tribe that loves raw chokeberries or bhut jolokia peppers?). The point is simply that taste objectivism deserves a better hearing than MacFarlane's hasty dismissal.

Response two: expertise. Kölbel and Wright appeal to the intuitive plausibility of faultless disagreements about taste, and offer relativism as a logically consistent account of that phenomenon. There is no denying that there is some intuitive appeal to thinking that in fundamental disputes about taste neither disputant is mistaken. On the other hand, there is a contrary and vigorous intuition that there are legitimate experts in matters of taste. Oenophiles rate wine vintages, assign points, and edit The Wine Advocate and The Wine Spectator. Beer aficionados rank beers by type and write books like The Beer Lover's Guide and 500 Beers to Try Before You Die. There are restaurant critics who award Michelin stars, or assessments for Zagat's. The World Pizza Championships give medals to pizza-makers in various categories. Whiskey, coffee, tea, caviar, sushi – all have their fan base and expert assessors who determine which are better and worse.

While it is certainly true that an average person may disagree with an expert about which beer, say, is more delicious, the obvious response is that the expert is presumptively right precisely because the average taster has an uneducated palate. One doesn't consult a punk rock fan for an opinion about last night's performance of the Eroica Symphony, and one doesn't consult a Budweiser drinker to adjudicate between Brooklyn Local One and Allagash Triple. The same holds for other sorts of perceptions: a novice medical student is less adept at reading an X-ray than a senior attending physician, even if both have perfect eyesight. Expert gustation, like reading X-rays, is a learned perceptual skill. The notion of experts about taste does not require unanimity among the experts, although it does assume considerable agreement among them. Beer experts may disagree among themselves whether Chimay Blue Grand Réserve is better than Rochefort Trappiste 8, but all will agree that both are better products than Budweiser. Kölbel complains that the assumption of objective normative facts about taste fails to explain the intuition that the deliciousness of a beer is less objective than how many are left in the refrigerator. However, relativism about taste fails to explain why we routinely acknowledge that there are bona fide experts about beer, wine, whiskey, etc. As far as intuitions about taste go, they do not come down squarely on the side of the relativists.

Again, I'm not defending taste absolutism; rather, I'm merely showing that taste absolutists do have some plausible moves to make against the taste relativists. The proper functioning and expertise responses are a sketch of how taste absolutists might reasonably stick to their strategy of continuing to argue until one side capitulates. Besides the continued argument solution, other approaches to gustatory disagreement are still on the (dining) table as well. One person could admit that, well, there are dishes in which rhubarb isn't as nasty as they originally thought it was, whilst their opponent also concedes that it is easy to prepare rhubarb poorly, in which case it is unpalatable (compromise). Or they may agree that rhubarb is in fact disgusting in certain culinary contexts but quite appetizing in others (ambiguity). Or the disputants may conclude that the most they can say about rhubarb is how it provisionally appears to each of them, and that they are in a state of aporia with respect to the true nature of aesthetics of rhubarb (Pyrrhonism).

To sum up: taste absolutists have a prima facie means of explaining disagreements away with the proper functioning and expertise arguments; they aren't faultless disagreements after all. We might as well stick with the first strategy of resolving disputes: keep arguing until someone capitulates. Furthermore, the other possible solutions of compromise, locating an ambiguity, and Pyrrhonism all remain live options for settling disputes of taste. Relativism as a solution to disagreement is adequately motivated when (1) we have uncovered a genuine irreconcilable difference, a disagreement that is epistemically irresolvable because there is no such thing as the right kind of evidence to settle it and (2) the alternative solutions to disagreement are not available. Predicates of personal taste have not met this standard.

Irreconcilable differences

When disputing parties agree as to what counts as basic evidence, there is room for non-relativist solutions to their disagreement. Two eyewitnesses might disagree about what they saw, and be unable to convince the other, but nevertheless they agree that the proper sort of evidence is visual. They disagree about the data, but not about the kind of data that is relevant. We saw that the same situation held for matters of taste. In the earlier example, our disputants about rhubarb agreed that the information relevant to its deliciousness (or lack thereof) involved the taste, smell and texture of rhubarb. It was just that, like the eyewitnesses, they disagreed about the data. Yet it is entirely reasonable to hold that there is an absolute truth of the matter and the disagreements arise out of the disputing parties possessing incompatible, but incomplete, evidence.

When a dispute concerns what even counts as basic evidence (and hence appropriate methods of getting evidence) for the subject matter at hand, then relativism begins to look like the only viable candidate for settling the disagreement.

Disagreement over basic evidence alone won't secure relativism, though. Consider a case in which there is

1. 1. disagreement over some claim P

2. 2. disagreement over what kind of evidence is relevant to settling (1)

3. 3. agreement over what kind of evidence is relevant to settling (2)

Here is a toy example. Suppose that Jack and Diane are disagreeing about the age of Earth. Jack maintains that P: Earth is approximately 4.5 billion years old. Diane denies P. In addition, Jack and Diane disagree about what kind of evidence is relevant to settling the dispute over P. Jack thinks that the appropriate evidence is the data provided by the latest geological radiometric dating techniques applied to ancient rocks and meteorites. Diane believes that the right evidence is instead the Bible and its interpreters (she is especially taken with the Venerable Bede's ecclesiastical derivation that Earth was created in 3952 BCE). So here we have a case of disagreement over a proposition P and also disagreement over the evidence relevant to settling the dispute over Before declaring an impasse, however, Jack and Diane realize that there is second-order evidence that bears upon the question of what the right kind of evidence is to settle the debate over P.

Both Jack and Diane agree that whatever the truth of P, any belief about the age of Earth needs to be coherently integrated into one's broader network of beliefs, and that any updating of one's belief-set needs to be as globally consistent as one can manage. That is, affirming or denying P must be part of a more general project of achieving wide reflective equilibrium in a comprehensive worldview. Jack then argues that Diane is unable to integrate the Venerable Bede's Earth-dating method with her other scientific beliefs. For example, she believes that Earth's crust is composed of massive plates that slowly move over a viscous mantle, throwing up volcanic mountain ranges and carving the continents. She also believes that helioseismic study of the pressure waves and convection turbulence in the sun tells us the ratio of hydrogen to helium in the sun's core and hence the age of the sun. Diane is further convinced that the existence of redshift in star spectra and the uniform distribution of a cosmic microwave background radiating at three degrees Kelvin are compelling reasons to accept Big Bang cosmology. Jack convinces Diane that these collateral scientific beliefs all point directly to the existence of deep time and are incompatible with a young Earth. Diane then gives up her belief that Bede and the Bible are the right kind of evidence to settle the dispute over P, and comes to agree with Jack that P is true.

In the Jack and Diane case, agreeing upon second-order evidence led to a domino effect that produced a nonrelativist solution to (1). However, it is in cases where there is no agreement as to what kind of second-order evidence is relevant to settling a first-order evidentiary dispute that the relativist solution looks promising. When negotiations over higher-order evidence break down, they break down comprehensively.

To illustrate such a collapse, let's modify the previous example. Instead of Jack and Diane disagreeing over the age of Earth, suppose they disagree over P': human beings each have a soul which animates their bodies and is immortal; it does not perish when it separates from the body at death, and it will be reunited with the body at the final Resurrection. Jack denies P' and Diane affirms it. Jack and Diane further disagree about what kind of evidence is relevant to settling their dispute. Jack maintains that the appropriate evidence is provided by the analytic rationalist methodology of contemporary philosophy of mind, including reflection on hypothetical cases, thought experiments, and appeals to intuition. Zombies, swampmen, Chinese rooms, C-fibers, and strangely reared neuroscientists figure prominently in Jack's reasoning. Diane avers that the appropriate evidence is provided by the Bible, along with its interpretation by the learned doctors of the church. Jack reports Jaegwon Kim's observation that there is an almost complete consensus among philosophers in rejecting the existence of an immortal spiritual soul.Footnote ¹⁹ Diane quotes The Catechism of the Catholic Church (pt 1, sec 2, ch 1, art 1, para 6, §366).

Thus far, Jack and Diane are in the same epistemic position they were in earlier, when they debated the age of Earth. They disagree about some proposition, and they disagree about the kind of evidence relevant to settling their dispute. Before, Jack and Diane agreed that they needed to be able to systematize their respective beliefs in wide reflective equilibrium, and that this requirement constituted a sort of second-order evidence. It was when Diane was unable to do so that she had to admit that radiometric dating really was the right kind of evidence to determine the age of Earth. While Jack and Diane still agree on the need for reflective equilibrium, in the present example it does not serve as a means of adjudicating between philosophical evidence and religious evidence. Diane, in line with classical theology, makes every effort to ensure that her religious-based beliefs about minds, souls, personal identity, and immortality are internally consistent, explanatorily cohesive and otherwise epistemically virtuous. Jack does the same for his rationalist-based beliefs. Yet they are still entrenched at inconsistent positions regarding P'.

In the present example, Jack and Diane have a genuine irreconcilable difference; they disagree over proposition P', they disagree over what evidence is relevant to establishing to truth or falsity of P', and they have no additional means of settling their debate about the relevant evidence. Jack and Diane cannot discover any mutually agreeable meta-evidence which would allow them to settle their dispute over first-order evidence. Clearly the strategy of continued argument is quixotic – as long as Jack and Diane endorse incompatible forms of basic evidence, reason will never compel one of them to capitulate. Perhaps they could compromise, although it is difficult to see how that might work. Human beings are partly composed of souls, but they are not immortal? We have immortal souls but there is no resurrection of the body? Bertrand Russell and St. Augustine are as liable to compromise on original sin.

One might suggest that Jack and Diane could compromise on the sources of basic evidence. Jack could admit that revelation and church authority are also forms of evidence, and Diane could agree that rational intuition is a basic source as well. Unfortunately, while such a compromise may eliminate disagreement over evidence, it will lead to contradictions in results. Agreeing though compromise that analytic rationalism and traditional theology are both legitimate methods to arrive at beliefs about souls is simply going to result in a belief that there are souls and a belief that there are not. Thus compromise does not settle the disagreement over P'.

Ambiguity approaches also do not look promising. Sometimes by ‘soul’ people in fact simply mean ‘mind’, but Jack and Diane have already ruled that out. She believes in the existence of an incorporeal, yet spatially-located substance that is incorruptible and eternal. Jack denies that claim. The finer-grained ambiguity strategy of contextualism is no better; there aren't situational or conversational contexts in which it is true that souls exist and others in which it is false. The existence of souls isn't context sensitive like gradable adjectives, indexicals, pronouns, or (possibly) knowledge.

The two remaining alternatives are Pyrrhonism and relativism.

Pyrrhonism looked like the appropriate response when (1) we'll never have enough evidence to settle a dispute, or (2) when we'll never have the right kind of evidence to settle one. One way to understand Jack and Diane's conflict over P' is as just another case of either (1) or (2). That is, either they can't get enough second-order evidence to determine what the appropriate first-order evidence is to resolve the truth-value of P', or they can't get the right kind of second-order evidence. If that's what's going on, then Pyrrhonism again seems to be the right move: Jack and Diane should suspend judgment about whether analytic rationalism or classical theology provides the appropriate evidence regarding the existence of souls, and thus suspend judgment about P'. I don't know how to decisively rule out this interpretation. Pyrrhonic skepticism is throwing in the towel, though – it settles a disagreement by getting the disputants to agree that they have no idea what to believe and will never have any idea about what to believe.

On the other hand, we might regard a persistent failure to agree about even the meta-evidence for a claim as a good reason to conclude that there is no such thing as the right kind of first-order evidence. In such a case, provided we are not tempted by scepticism, relativism appears to be our last option. The dispute between Jack and Diane is resolved by determining that P' is both true and false. P' is true relative to Diane's perspective, a perspective which includes as an epistemological component the methodology of appeal to revelation, the Bible, and its expert interpreters as a source of noninferential beliefs. P' is false relative to Jack's perspective, the epistemology of which includes analytic rationalism.

Obviously, I am merely gesturing towards the sort of shape an adequate relativism should take, and not developing a theory of relativism here. However, I have shown the kind of scenario that properly motivates the relativist strategy. As long as parties to a dispute believe that they have room for movement, they continue to argue in the hopes of forcing the other to capitulate. When they take themselves to be merely chewing up the same ground over and over, without either party advancing, the options of seeking a compromise or locating an ambiguity begin to look appealing. When the disputants agree on the sort of evidence relevant to settling the disagreement, but hold that they will never have enough evidence, or never have the right kind of evidence, then the Pyrrhonic eternal suspension of judgment seems appropriate. It is when there does not appear to be any such thing as the right kind of evidence that relativism may be the right approach. Disagreements regarding matters of personal taste – frequently offered as the best drivers of relativism – are not deep enough to build a relativism upon. The other disagreement-solving strategies are not adequately ruled out in taste cases, not even keep arguing until capitulation. Relativism is motivated by irreconcilable differences, differences that arise when disputants cannot even agree on the meta-evidence for a contested proposition. In such a case they may reasonably conclude that they are both right, relative to separate perspectives. Thus can their disagreement be resolved.Footnote ²⁰