Evolutionary Debunking Arguments in Ethics

by

Diego E. Machuca

• LAST REVIEWED: 26 October 2022
• LAST MODIFIED: 22 February 2018
• DOI: 10.1093/obo/9780195396577-0366

Introduction

There are at least three different genealogical accounts of morality: the ontogenetic, the sociohistorical, and the evolutionary. One can thus construct, in principle, three distinct genealogical debunking arguments of morality, i.e., arguments that appeal to empirical data, or to an empirical hypothesis, about the origin of morality to undermine either its ontological foundation or the epistemic credentials of our moral beliefs. The genealogical account that has been, particularly since the early 2000s, the topic of a burgeoning line of inquiry in the metaethical literature is the one that explains the origin of moral thinking by appealing to Charles Darwin’s theory of evolution through natural selection. For this reason, when it comes to genealogical debunking arguments, it is various types of evolutionary debunking argument (EDA) that are the focus of the current debate between moral skeptics and moral realists. Evolutionary moral debunkers maintain that the capacity to make moral judgments is an evolved trait—a view accepted by most of their detractors. They maintain, in addition, that such a capacity is an adaptation—i.e., a trait selected for because it enhances reproduction and survival—and not merely either a by-product of an adaptation or an evolutionary accident—a view accepted by fewer of their detractors. Roughly put, the thrust of EDAs is that biological evolution is aimed, not at moral belief-forming processes that are reliable, but at moral belief-forming processes that are adaptive. In other words, the evolutionary function of those processes is not that of tracking the moral truth: their general success at matching or accurately representing allegedly objective or attitude-independent moral facts, properties, or truths explains neither their emergence nor their persistence. Humans are therefore disposed to make moral judgments regardless of the evidence to which they are exposed, regardless of whether there are or are not objective moral facts, properties, or truths. In the contemporary scene, the most important and influential EDAs are those advanced by Richard Joyce and Sharon Street. Although Joyce’s EDA is more elaborate than Street’s inasmuch as it is based on a detailed evolutionary account of morality, it is Street’s EDA that has received the most attention among those seeking to defend moral realism against EDAs. If an EDA can establish at most an epistemological conclusion, then it could be argued that Joyce’s argument (at least the version defended in his later works) is superior to Street’s given that the conclusion of the former is epistemological whereas that of the latter is ontological. Indeed, while Joyce’s EDA is taken to support epistemological moral skepticism, according to which our moral beliefs are epistemically unjustified, Street’s is taken to support moral anti-realism (moral constructivism in particular), according to which attitude-independent moral facts do not exist.

Overviews

Several accessible general presentations of the evolutionary account of morality, the distinct debunking arguments based thereon, and the various replies to these arguments are available. Schroeder 2001 and FitzPatrick 2008 are encyclopedia entries on evolutionary ethics in general, but only the latter offers a thorough, updated, and authoritative overview. Allhoff 2003 offers an outline of the history of evolutionary ethics from its beginnings to the second part of the 21st century. Machery and Mallon 2010 provides a clear presentation and a critical examination of the different versions of the claim that morality is a product of biological evolution. Vavova 2015 and especially Wielenberg 2016 provide fine overviews of the contemporary metaethical discussion of evolutionary debunking arguments (EDAs).

• Allhoff, Fritz. “Evolutionary Ethics from Darwin to Moore.” History and Philosophy of the Life Sciences 25.1 (2003): 51–79.

  DOI: 10.1080/03919710312331272945

  After dividing the history of evolutionary ethics into three stages, namely, development, criticism and abandonment, and revival, Allhoff focuses on the first two stages on the grounds that they are those regarding which the philosophical merits have already been largely decided.

• FitzPatrick, William. “Morality and Evolutionary Biology.” In Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. Stanford, CA: Stanford University, 2008.

  Updated in 2014, this entry provides (i) an overview of the basic issues and distinctions in evolutionary ethics, and offers a critical examination of (ii) descriptive evolutionary ethics, (iii) the connection between evolutionary biology and normative ethics, and (iv) evolutionary metaethics, taking into account the main EDAs advanced in the literature and the replies thereto.

• Machery, Edouard, and Ron Mallon. “Evolution of Morality.” In The Moral Psychology Handbook. Edited by J. Doris and the Moral Psychology Research Group, 3–46. Oxford: Oxford University Press, 2010.

  DOI: 10.1093/acprof:oso/9780199582143.003.0002

  Distinguishes three versions of the claim that morality is a product of biological evolution—what has evolved are some components of moral psychology, or normative cognition in general, or moral cognition in particular—and critically reviews the empirical evidence in support of each one of them.

• Schroeder, Doris. “Evolutionary Ethics.” In Internet Encyclopedia of Philosophy. Edited by J. Fieser. Martin: University of Tennessee, 2001.

  Presents some of the key figures and concepts in evolutionary ethics, its contribution to the different areas of ethics, and some of the challenges it faces. The entry is excessively brief and has not been updated since its first publication in 2001, which means that it does not take account of the vast body of literature on the evolutionary debunking of morality published in the last fifteen years.

• Vavova, Katia. “Evolutionary Debunking of Moral Realism.” Philosophy Compass 10.2 (2015): 104–116.

  DOI: 10.1111/phc3.12194

  Distinguishes three different EDAs implicit in the literature and claims that only one of them appeals to evolution in a way that prevents the argument from collapsing into a more general skeptical argument. It also considers several objections to that evolutionary argument, which are found deficient, and proposes an allegedly promising rescue for moral realism.

• Wielenberg, Erik. “Ethics and Evolutionary Theory.” Analysis 76.4 (2016): 502–515.

  DOI: 10.1093/analys/anw061

  Presents the EDAs advanced by Richard Joyce and Sharon Street, examines the various ways in which these EDAs have been interpreted in the literature and the main responses that have been offered to them, and identifies some new issues for future research.