MORAL REALISM AND EXPERT DISAGREEMENT.

• Author: Singh, Prabhpal

1. Introduction

   Consider moral realism a genus of views whose species share each of the following three tenets:

   (i) Moral sentences, statements, judgments, and beliefs are propositions capable of being either true or false.

   (ii) Some moral sentences, statements, judgments, beliefs, or propositions are true.

   (iii) The truth-values of moral propositions are 'stance-independent' (Shafer-Landau 2003: 15), meaning the truth or falsity of any given moral proposition is independent of any person's or groups' attitudes, preferences, or opinions toward it.

   The thesis of moral realism is the conjunction of these three sub-theses (1) (McGrath 2010: 60-61, Shafer-Landau 2006: 209, 2013: 54, Horn 2017: 363, Horn 2020). While specific realist accounts differ in how they further formulate themselves, they are all species of the genus moral realism, and so inherit their genus' essential features. Understood this way, moral realism is a genus of meta-ethical views on which morality is an objective (2) matter in that moral beliefs have non-relativistic truth-values and at least some of those beliefs are true (Wedgwood 2014: 23). Accordingly, there are objective moral facts, and moral questions have objectively true answers. One may understand moral anti-realism as the opposite of this. Simply, moral anti-realism is the denial of the objectivity of morality, and therefore the denial of the claim that there are objective moral facts or objectively correct answers to moral questions.

   One of the major challenges for moral realism is explaining why there remains widespread and longstanding disagreement amongst expert moral philosophers. Moral philosophers as a community disagree on issues ranging from questions about general moral principle and theories (such as utilitarianism or deontology) to questions about particular moral issues (such as what we ought to do about climate change, or whether abortion is wrong, etc.). After all, it seems reasonable to expect experts to tend towards consensus on the issues they have expertise in. This does not appear to be the case in moral philosophy. Moral philosophers disagree on a range of topics pertaining to morality and have disagreed on such matters for centuries.

   When laypeople disagree on some issue, it is reasonable to think that such disagreement is a result of at least one party's epistemic failing. It is also reasonable to think that when one is an expert on some issue, they will not suffer the same epistemic failings as laypeople. We might then think there would be less disagreement on issues between those who are experts on those issues than there is between laypeople. However, this is not the case with moral philosophy. There is widespread and longstanding disagreement between expert moral philosophers, that is, those who are educated in and supposedly knowledgeable about issues in moral philosophy. If moral philosophy is a domain in which even the supposed experts radically disagree, what does this indicate about the objectivity of morality?

   In this paper, I present three arguments against the anti-realist explanation of widespread and longstanding disagreement amongst expert moral philosophers. First, I argue that arguments from expert disagreement face a problem of overgeneralization that leads to their self-undermining. If we accept the abductive inference from expert disagreement to moral anti-realism, we can construct an analogous argument from meta-ethical disagreement to show that moral anti-realism is false. Second, because the moral anti-realist makes a probabilistic abductive inference from expert disagreement to moral anti-realism, theirs is an 'inference to the best explanation' style argument. I show that this sort of argument for moral anti-realism is also selfundermining as it allows enough normativity to posit objective moral facts. Third, I consider how both agreement and disagreement have been used to arrive at an anti-realist conclusion and argue that neither has any evidential value for moral anti-realism or against moral realism. I conclude that widespread and longstanding disagreement amongst expert moral philosophers is not a problem for moral realism.

2. Expert disagreement, and the state of moral philosophy

   Pioneered by John L. Mackie (1977), standard arguments from disagreement have typically focused on interpersonal and cross-cultural disagreement, or 'folk' disagreement. David Enoch (2009) has argued that a variety of these folk arguments from disagreement do not pose a threat to moral realism. However, the argument I wish to consider here differs from these more familiar arguments from folk disagreement. The central concern is the disagreement and lack of consensus amongst experts. When laypeople disagree on some issue, say, whether vaccines are safe and effective, or the shape of the earth, or whether evolution explains the diversity of life on earth, the source of the disagreement is that at least one party is in error. The error in play will be some sort of epistemic shortcoming or defect, such as being ignorant of some relevant facts, being biased or prejudiced toward certain pieces of evidence or argument, being dogmatic, etc. Folk disagreement is often due to these kinds of epistemic errors. Things are different when talking to medical professionals, or geologists, or biologists. The difference is that we expect these people not to be in the sort of disagreement often seen between laypeople. This is because medical professionals, geologists, and biologists are experts in their respective fields. If there is a tendency amongst practitioners of a certain discipline of inquiry toward consensus it is sometimes taken as a sign their discipline is an objective one in the sense that it arrives at objectives truths. It is sometimes taken as a reason in favour of the reliability of a discipline's methodologies that they result in or tend towards consensus amongst experts in that discipline. It would be most perplexing to see socalled experts locked in widespread and longstanding disagreement, and it would be concerning to see them in such a state if their respective discipline was one which purported to aim at and reveal objective truths. The discipline of moral philosophy is exactly in this predicament.

   What is to be made of the fact that there is such widespread and radical disagreement amongst expert moral philosophers? One possible explanation is simply that radical disagreement amongst moral philosophers is a result of morality's lack of objectivity. This would mean the thesis of moral realism, the family of views which takes morality to be an objective matter, is false. Taking this explanation seriously is to jettison the idea that morality is an objective matter, and therefore espouse moral anti-realism. Brian Leiter (2014) takes such an approach and defends Nietzsche's version of the argument from disagreement for the denial of the objectivity of morality, arguing that anti-realism about morality is the best explanation for widespread and longstanding moral disagreement amongst expert moral philosophers. It is an argument from expert disagreement. If it is the case that moral philosophers throughout history can engage in moral theorizing, but after centuries still not arrive at a consensus all the while radically disagreeing with each other, it would appear there is neither movement toward rapprochement between the competing moral traditions (Leiter 2014: 140) and thus no progress in moral philosophy, nor that moral facts are epistemically accessible. Thus, we cannot reasonably posit objective moral facts.

   The Nietzschean anti-realist explanation for this is that morality is not an objective domain. Looking at the most sophisticated moral theories of the Western analytic philosophical tradition, Nietzsche observes that a group of moral philosophers who share similar beliefs, practices, and many of the same judgments on concrete moral cases, remain in radical disagreement on the most important and foundational matters of moral theory (Leiter 2014: 134-135). Leiter (2014: 131) describes this as "the single most important and embarrassing fact about the history of moral theorizing by philosophers over the last two millennia".

   Nietzsche's observation is equally pertinent to contemporary moral theory as it is to the history of moral philosophy. In recent empirical work, David Bourget and David J. Chalmers (2014) published results of a survey of 1,972 professional philosophers from around the world (though with an acknowledged analytic and Anglo-centric bias) asking what philosophical views they held on 30 central philosophical issues. The issue of 'Normative Ethics' produced the following results: "deontology 25.9%; consequentialism 23.6%; virtue ethics 18.2%; other 32.3%" (Bourget and Chalmers 2014: 476). As is evident from Bourget's and Chalmers' survey results, Nietzsche's observation about professional moral philosophers in the Western analytic tradition holds for contemporary moral philosophers as well, for the empirical evidence shows they are in radical disagreement.

   I take the Nietzschean view to be essentially denying moral philosophy's status as a Wissenschaft, and therefore denying the possibility for moral theorists to find anything like 'objective truth' in their endeavour. If moral philosophy is not a Wissenschaft, then moral theorizing is not genuine inquiry aiming at truth. One of Nietzsche's principal critiques of the history of moral philosophy is that the variety of moral theories Nietzsche's targets think can be dialectically justified are "necessarily sophistical" (Nietzsche in Kaufmann and Hollingdale 1968: 233). Nietzsche seems to mean that while attempts at the dialectical justification of the central and enduring moral philosophies of the Western analytic tradition can be made, all such attempts will fail (Leiter 2014: 138). Moral philosophy contrasts with other disciplines. Other disciplines, such as the natural...