The Epistemic Significance of Disagreement

J. Matheson

• Publisher: Palgrave Macmillan
• Year: 2015
• ISBN:
  9781137400901
• Topic: Philosophy
• Subtopic: Epistemology in Philosophy

Discovering someone disagrees with you is a common occurrence. The question of epistemic significance of disagreement concerns how discovering that another disagrees with you affects the rationality of your beliefs on that topic. This book examines the answers that have been proposed to this question, and presents and defends its own answer.

1

Introduction

The world is rife with disagreement. Disagreements range from trivial matters – such as who will win next year’s Super Bowl, which vacation destination gives you the most bang for your buck, and what wine pairs best with dinner – to matters of greater consequence – such as whether God exists, whether we have free will, and whether it is morally permissible to eat meat. That these disagreements exist is uncontroversial. If in doubt, a five-minute conversation with the person sitting at the neighboring table at your favorite coffee shop will clear up the matter. Even the most like-minded individuals do not agree about everything, and a group does not need to be very large to prevent consensus on a large number of issues.

It is common to hear expressions such as “let’s agree to disagree” and “reasonable people disagree”, but how much truth is behind such slogans? We have all reached points in a debate where it became obvious that further dialogue would be fruitless. The phrase “let’s agree to disagree” is often used at such points to disband the discussion. But is there more to this slogan? While we might be agreeing that we will continue to have conflicting views, does it commit us to believing that we are each equally rational in continuing to hold those views? More importantly, whether or not the phrase commits us to these consequences, is it true that we can be equally rational in holding these divergent opinions? And if so, under what circumstances?

Similarly, saying “reasonable people disagree” seems to convey a truth, but in what sense? Are there people who are in general reasonable people, but who also happen to have conflicting opinions on some matter? It sure seems so. Are there also people who are reasonable in holding their particular conflicting opinions on some topic? And if so, under what circumstances?

Given that disagreements exist and that we are aware of them, what affect, if any, should our awareness of them have on what we believe? In particular, how does our awareness of such disagreements affect the rationality of our own beliefs on these topics? Can I rationally maintain my religious, philosophical, political, and scientific beliefs once I am aware of the widespread disagreement among the experts in these fields?

When confronted with a disagreement, some people become less confident in their view. Others are emboldened by the disagreement and dig their heels in further. Still others are interested yet unmoved by the discovery of disagreement. But how should we respond to disagreement? What is the rational reaction? What is epistemically called for on our part?

These questions are central to the debate on the epistemic significance of disagreement and are the fundamental questions addressed in this book. These questions are normative questions; they are not merely descriptive questions about the existence of various disagreements or about how people do in fact respond to them. They are about how people should respond to disagreement. They are also epistemic questions. They are about the epistemic status of various beliefs in light of disagreement about them. Our focus is on the doxastic responses to disagreement. There may be a number of actions that are rational to undergo upon discovering a disagreement, but our focus is on what should (and should not) be believed in such situations.

While the existence of disagreement is uncontroversial, what rationality demands of us in the face of disagreement is anything but. Throughout this book a number of answers that have been proposed to these questions will be explained and evaluated. Along the way I defend a somewhat radical view on the epistemic significance of disagreement. According to this view, disagreement has a much more dramatic impact on the rationality of our beliefs than is typically thought. In particular, I defend the claim that awareness of widespread disagreement on controversial issues in religion, philosophy, politics, and science has the consequence that we are much less epistemically justified in our controversial beliefs on those matters and that we often are not epistemically justified in holding them at all.

1.1 An early challenge: relativism and anti-realism

At this early point some eyebrows might already be raised. Those inclined toward a naïve and pervasive relativism might chime in: ‘Sure, we have different beliefs on these matters, but there is some sense in which we don’t really disagree since we can all be correct. After all, everything’s relative!’ If there are not objective facts under dispute, or if truth is radically indexical, then the ‘disagreements’ mentioned above are merely apparent disagreements. They are no more instances of a disagreement than when one child yells ‘I’m hungry!’ and another child screams back ‘I’m not hungry!’ These two children may be yelling at each other, and they may be taking themselves to be engaged in a disagreement, but there is no fact that they are disputing. Such a ‘disagreement’ is merely apparent, and the children have been confused by their words and are talking past each other. If everything is relative, then the ‘disagreements’ mentioned above are similarly merely apparent disagreements since there is no objective fact of the matter to be under dispute.

While such a version of relativism is not the focus of this book, it is important to set it aside from the outset. There are strong reasons to reject such a view, and it is worth briefly considering them here. To begin with, such a view is either self-defeating or without motivation. Consider the claim ‘everything is relative.’ Is that claim itself relative? If it is, then each of us would need a special reason to think that it was also ‘true-for’ each of us. If the claim is not objectively true (true across the board), then it is only ‘true-for’ some individual or group – its truth is relative. So, the claim in question being ‘true-for’ the speaker would give us no reason for thinking that it is also ‘true-for’ the hearer. Just as one child’s being hungry does not (on its own) make it more likely that the other child is hungry, making a case that relativism is ‘true-for’ the speaker does nothing to make a case that relativism is also ‘true-for’ the hearer. So, on this interpretation the claim ‘everything is relative’ is without motivation. Worse, if this claim is true and yet not relative, then the claim must be objectively true. If the claim is true, but not simply ‘true-for’ some individual or group, then the claim must be just plain true – objectively true. However, such a truth is precisely the kind of truth our claim proclaimed to not exist! On this interpretation the claim is self-defeating; its truth entails its falsity. It is like the claim ‘no true English sentence has more than three words.’ This claim too is self-defeating; it cannot be true by its own standards. So, since the claim ‘everything is relative’ must itself either be relative or objective, and since there are problems for either way of interpreting the claim, there are good reasons to reject the claim that everything is relative.¹

However, even if such a pervasive or global relativism cannot be correct, this does not entail that the domains rife with disagreement are not themselves relative. The existence of widespread and persistent disagreement within a domain has often served as a premise in arguments that there are not objective facts in that domain. In particular, widespread and pervasive ethical disagreements have been taken to be an indication that morality is either relative or in some sense not ‘real’ (i.e. lacking a truth-value altogether).

However, the appeal to disagreements in a domain to support the relativity or ‘unreality’ of a claim within a particular domain is puzzling. Let’s begin by examining such an argument for ethical relativism. Ethical subjectivism is a species of ethical relativism that claims that the standards of morality are relative to individuals. So, on this view, a speaker’s moral claim is true just in case it correctly reports the beliefs and attitudes of that speaker. So, while one speaker might say ‘X is wrong’ and another speaker say ‘X is not wrong’, if each speaker is (correctly) using different ethical standards, not only can both assertions be true, there is no sense in which they are in conflict. The only way to have an ethical disagreement according to ethical subjectivism is to have a disagreement about one of the speaker’s attitudes and beliefs. So, to the extent that our ethical disagreements amount to more than disagreements about our own attitudes and beliefs, we have reason to believe that ethical subjectivism is false.

Similar considerations apply to views that make the ethical standards relative to groups. According to cultural relativism an action is morally permissible just in case it is approved of by one’s culture. When there are intercultural ethical disagreements, cultural relativism is committed to the same consequence as ethical subjectivism. In such cases, different ethical standards are (correctly) in play, and so, the only way to truly disagree is to dispute what the other individual’s culture accepts. In intra-cultural disagreements, the parties of the disagreement share the same cultural standards and thus, according to cultural relativism, the same ethical standards. However, according to cultural relativism, such disagreements simply reduce to disagreements about what the said culture approves of. So, to the extent that our intra-cultural ethical disagreements are not simply disagreements about what that culture accepts, we have reason to believe that cultural relativism is false.

The argument from widespread and persistent disagreement in some domain to anti-realism in that domain does not fare any better. According to ethical non-cognitivism, moral claims do not express propositions and are thus neither true nor false. Some have taken it that widespread and persistent moral disagreement is evidence that morality is not ‘real’, that in making moral claims we are merely expressing emotion or prescribing certain actions. On this view, when one person claims ‘X is wrong’ and another person claims ‘X is not wrong’, neither individual is making an assertion, and there is no fact that the two disagree about. These individuals can have conflicting attitudes, according to non-cognitivism, but one party is not accepting some ethical proposition that the other rejects.² So, rather than being supported by the disagreements in some domain, anti-realist views must posit that we do not have cognitive disagreements in that domain. To the extent that we have reason to believe that there are genuine cognitive disagreements in a domain, we also have reason to be realists about that domain.

So, contrary to how some have taken it, the existence of genuine disagreements in some domain actually points to the objectivity of that domain. In addition, there are good reasons to believe that some claims in these controversial domains are not relative. To see these reasons, consider the disagreement about the existence of God. Once we fix on a particular conception of God, either there is such a being that exists or there is not. It cannot be that there both is and there is not such a being that exists. So, if one individual believes that God exists, and another disbelieves that very same claim, then they cannot both be correct, and at least one of them must be correct. This is not to say that we are always in a position to determine who is correct about a disputed matter. In fact, the view defended here has somewhat skeptical consequences concerning controversial matters. However, we need to be careful to distinguish the existence of an objective fact from our epistemic access to that fact.

I take it that similar considerations apply to debates about the existence of free will, the permissibility of eating meat, and the correct account of the quantum world. This is not to say that we are never simply talking past each other when engaged in debates about these issues. It is likely that some disputes about politics, religion, philosophy, and science are merely verbal disputes resulting from parties using their terms in different ways or not correctly understanding their opponents. But while some disputes in these domains are merely apparent disagreements, many are not – many are genuine disagreements. That said, I will not further defend the objectivity of religion, philosophy, or science here. I will be setting aside any relativistic and anti-realist worries in what follows, and I will be taking it that the disagreements in question concern objective facts. Readers with a relativistic or anti-realist bent on these matters are welcome to stick around. They can treat the central question of this book as a hypothetical: if there are objective facts in these domains, then how should discovering a disagreement about one of these matters affect what we believe about it?

1.2 Terminology and assumptions

Before we dig any deeper into the debate, it is important to set some groundwork by defining some key terms and laying out some assumptions. This book is about disagreement, but what is disagreement? Two individuals genuinely disagree about a proposition just in case they have adopted incompatible doxastic attitudes toward that proposition. For example, if two individuals agree on a particular conception of God, and one of them is an atheist (she disbelieves that God exists) and the other is a theist (she believes that God exists), then those two individuals genuinely disagree about the existence of God.

Given this example, it is tempting to think that incompatible doxastic attitudes are such that they cannot both be correct. After all, in our example the theist and the atheist cannot both be correct. While incompatible doxastic attitudes often cannot both be correct, these are in fact distinct properties. To see this, it will be helpful to elaborate on the nature of doxastic attitudes.

1.2.1 Doxastic attitudes

Doxastic attitudes are often seen as ‘all-or-nothing’ affairs. Such a doxastic picture is typically coupled with a tripartite taxonomy where one’s doxastic options are limited to three all-or-nothing attitudes: belief, disbelief, and withholding/suspension of judgment. On this way of viewing things, when one considers a proposition, one has three options: (i) believe it – conclude the proposition is true; (ii) disbelieve it – conclude the proposition is false; or (iii) withhold judgment – neither conclude that it is true nor conclude that it is false. These three attitudes represent three exhaustive and incompatible responses to a proposition.³ So, returning to our example above, the agnostic (one who withholds on whether God exists) is also in a genuine disagreement with both the theist and the atheist.

However, not everyone endorses this tripartite doxastic taxonomy. Others view the doxastic landscape in a far more fine-grained way and instead pick out degrees of belief or credences. Here, doxastic attitudes can be as precise as single point values on a 0–1 scale (inclusive) or a range of probability functions. On this scale, ‘0’ represents a maximal confidence that the proposition is false, and ‘1’ represents a maximal confidence that the proposition is true. The numbers between 0 and 1 proportionally represent a less than maximal degree of confidence.

Such a richer doxastic landscape seemingly escalates the potential for disagreement since different degrees of belief appear to be incompatible doxastic attitudes.⁴ For instance, there is a sense in which two theists, one who has a degree of belief of 0.7 that God exists, and the other who has a degree of belief of 0.9 that God exists, are engaged in a genuine disagreement. Whether we view such a disagreement as a disagreement of confidence or a doxastic disagreement will depend upon which doxastic picture we adopt.

There is reason to be dissatisfied with each of these doxastic pictures. The tripartite taxonomy fails to capture the richness of doxastic attitudes. There can be significant doxastic differences between two attitudes that both qualify as beliefs on this picture. The tripartite taxonomy simply fails to capture this. On the other hand, the degreed picture of belief artificially imposes a quantitative precision on our doxastic attitudes that just does not appear to be there. For instance, it’s hard to comprehend what a 0.764 degree of belief amounts to. Rather, the distinctions between doxastic attitudes appear to be qualitative rather than quantitative. For this reason a qualitative account of our doxastic attitudes, one that also reco...

Table of contents

• Cover
• Title
• 1  Introduction
• 2  Idealized Disagreement
• 3  Steadfast Views of Disagreement
• 4  Conciliatory Views of Disagreement and the Equal Weight View
• 5  Objections to the Equal Weight View
• 6  Everyday Disagreements
• 7  Objections
• 8  Conclusion
• Notes
• Bibliography
• Index