¹ The same descriptive/normative distinction serves as an organizing principle in Kahan, D. and Nussbaum, M., ‘Two Conceptions of Emotion in Criminal Law’, Columbia Law Review 96 (1996), pp. 269–374CrossRefGoogle Scholar. They diagnose what they see as inconsistencies in the law's prescriptions about emotion, and argue that those inconsistencies stem from the lack of a consistent general theory of what emotions are. We are convinced that the term ‘emotion’ expresses an extremely heterogeneous category and that there are empirical reasons to doubt that such a unified theory of emotions will be forthcoming; see Griffiths, P., What Emotions Really Are: The Problem of Psychological Categories (Chicago, 1997)CrossRefGoogle Scholar. Rather, we suspect that each emotion will have to be examined and assessed on its own, and in light of its particular character.

² For a full defence of the view, see Kelly, Daniel, Yuck! The Nature and Moral Significance of Disgust (Cambridge, 2011)Google Scholar.

³ Joseph Henrich, Steven Heine and Ara Norenzayan begin an important article on human psychological variation and diversity with a memorable example: ‘In the tropical forests of New Guinea, the Etoro believe that for a boy to achieve manhood he must ingest the semen of his elders. This is accomplished through ritualized rites of passage that require young male initiates to fellate a senior member. In contrast, the nearby Kaluli maintain that male initiation is only properly done by ritually delivering the semen through the initiate's anus, not his mouth. The Etoro revile these Kaluli practices, finding them disgusting’ (Henrich, Joseph, Heine, Steven and Norenzayan, Ara, ‘The Weirdest People in the World’, Behavioral and Brain Sciences 33 (2010), pp. 61–135, at 61)CrossRefGoogle Scholar.

⁴ Kass, L., ‘The Wisdom of Repugnance’, The New Republic 216.2 (1997)Google ScholarPubMed, <http://www.catholiceducation.org/articles/medical_ethics/me0006.html>; Kass, L., Life, Liberty, and the Defense of Dignity: The Challenge to Bioethics (New York, 2002)Google Scholar.

⁵ Nussbaum, M., ‘“Secret Sewers of Vice”: Disgust, Bodies, and the Law’, The Passions of the Law, ed. Bandes, Susan (New York, 1999), pp. 19–63Google Scholar; Hiding from Humanity: Disgust, Shame, and the Law (Princeton, 2004); ‘Danger to Human Dignity: The Revival of Disgust and Shame in the Law’, The Chronicle of Higher Education 50.48 (2004), p. B6; ‘Replies’, Journal of Ethics 10 (2006), pp. 463–506; From Disgust to Humanity: Sexual Orientation and Constitutional Law (Oxford, 2010).

⁶ For instance, see Kekes, J., ‘Disgust and Moral Taboos’, Philosophy, 67 (1992), pp. 431–46CrossRefGoogle Scholar; Abrams, K., ‘Fighting Fire with Fire: Rethinking the Role of Disgust in Hate Crimes’, California Law Review 90 (2002), pp. 1423–64CrossRefGoogle Scholar; Kulinowski, K., ‘Nanotechnology: From “Wow” to “Yuck”’, Bulletin of Science, Technology & Society 24 (2004), pp. 13–20CrossRefGoogle Scholar; Raikka, J. and Rossi, K., ‘Bioethics and The Moral Significance of “Gut Feelings”’, Türkiye Klinikleri Journal of Medical Ethics, Law and History 12 (2004), pp. 79–82Google Scholar; Turner, L., ‘Is Repugnance Wise? Visceral Responses to Biotechnology’, Nature Biotechnology 22 (2004), pp. 269–70CrossRefGoogle ScholarPubMed; de Grey, A. D. N. J., ‘Life Extension, Human Rights, and the Rational Refinement of Repugnance’, Journal of Medical Ethics, 31 (2005), pp. 659–63CrossRefGoogle ScholarPubMed; Deigh, J., ‘The Politics of Disgust and Shame’, Journal of Ethics 10 (2006), pp. 383–418CrossRefGoogle Scholar; Hauskeller, M., ‘Moral Disgust’, Ethical Perspectives: Journal of European Ethics Network 13 (2006), pp. 571–602CrossRefGoogle Scholar; Arneson, R., ‘Shame, Stigma, and Disgust in the Decent Society’, The Journal of Ethics 11 (2007), pp. 31–63CrossRefGoogle Scholar; Douard, J., ‘Loathing the Sinner, Medicalizing the Sin: Why Sexually Violent Predator Statutes are Unjust’, International Journal of Law and Psychiatry 30 (2007), pp. 36–48CrossRefGoogle ScholarPubMed; Kaebnick, G., ‘Reasons of the Heart Emotion, Rationality, and the “Wisdom of Repugnance”’, Hastings Center Report 38 (2008), pp. 36–45CrossRefGoogle Scholar; Niemela, J., ‘What put the “Yuck” in the Yuck Factor?’, Bioethics 25 (2010), pp. 267–79Google Scholar. As many of these authors point out, the interest in disgust has deeper historical roots; for instance see Devlin, P., The Enforcement of Morals (Oxford, 1965)Google Scholar. In this article, we focus on Kahan not just for clarity and ease of exposition, but because we think he has given the best and most worked out arguments in favour of the normative value of disgust.

⁷ See e.g. Midgley, M., ‘Biotechnology and Monstrosity: Why We Should Pay Attention to the “Yuk Factor”’, The Hastings Center Report 30 (2000), pp. 7–15CrossRefGoogle ScholarPubMed; Kass, Life, Liberty, and the Defense of Dignity; Salles, A. and Melo-Martin, de, ‘Disgust in Bioethics’, Cambridge Quarterly of Healthcare Ethics 21 (2012), pp. 267–80CrossRefGoogle ScholarPubMed.

⁸ See e.g. Nussbaum, Hiding from Humanity and Kelly, Yuck!.

⁹ Rozin, P., ‘The Process of Moralization’, Psychological Science 10 (1999), pp. 218–21CrossRefGoogle Scholar.

¹⁰ See e.g. Tybor, Joseph, ‘Unusually Creative Judges Now Believe Some Punishments Can Fit’, Chicago Tribune, 3 July 1988Google Scholar.

¹¹ Miller, W., The Anatomy of Disgust (Cambridge, 1997)Google Scholar.

¹² Kahan, D., ‘The Progressive Appropriation of Disgust’, The Passions of the Law, ed. Bandes, Susan (New York, 1999), pp. 63–79, at 64Google Scholar.

¹³ Kahan, ‘The Progressive Appropriation of Disgust’, p. 69.

¹⁴ Kahan, ‘The Progressive Appropriation of Disgust’, p. 72. Kahan suggests that a historical analysis would show that ‘all societies inevitably make use of disgust to inform their judgments of high and low, worthy and unworthy’ (p. 64).

¹⁵ Kahan, ‘The Progressive Appropriation of Disgust’, p. 73.

¹⁶ Kahan, ‘The Progressive Appropriation of Disgust’, p. 71 (italics in original).

¹⁷ See, e.g. Armstrong, W. S., ‘“Ought” conversationally implies “can”’, The Philosophical Review 93 (1984), pp. 249–61CrossRefGoogle Scholar.

¹⁸ Since Kahan is working with a different and generally more plausible account of the character of disgust, different arguments than those made against advocates like Kass are needed to rebut Kahan's normative conclusions. See, Kelly, Yuck!, pp. 137–52.

¹⁹ See e.g. H. Chapman and Anderson, A., ‘Things Rank and Gross in Nature: A Review and Synthesis of Moral Disgust’, Psychological Bulletin 139.2 (2013), pp. 300–27Google Scholar. See also May, ‘Does Disgust Influence Moral Judgment?’, Australasian Journal of Philosophy (DOI: 10.1080/00048402.2013.797476) for some doubts about a few of the earliest and most cited experiments, though.

²⁰ Which is not to say we are without reservations about this claim. Our worries stem from the fact that disgusting things are naturally conceived as contaminated and contaminating, and so polluting to anything with which they come into physical (or even symbolic) contact. Because of this, we suspect disgust will be difficult to contain, or aim with any degree of precision. In light of this, we think it a dubious idea to put so unreliable an instrument at anyone's disposal: a tool that cannot be controlled is a bad tool.

²¹ Young, L. and Saxe, R., ‘When Ignorance is no Excuse: Different Roles for Intent across Moral Domains’, Cognition 120 (2011), pp. 202–14CrossRefGoogle ScholarPubMed; Russell, P. and Giner-Sorolla, R., ‘Moral Anger, but Not Moral Disgust, Responds to Intentionality’, Emotion 11 (2011), pp. 233–40CrossRefGoogle ScholarPubMed. See also, Hodson, G. and Costello, K., ‘Interpersonal Disgust, Ideological Orientations, and Dehumanization as Predictors of Intergroup Attitude’, Psychological Science 18 (2007), pp. 691–8CrossRefGoogle Scholar for more on disgust and dehumanization.

²² Harris, L. T. and Fiske, S. T., ‘Dehumanizing the Lowest of the Low: Neuro-imaging Responses to Extreme Out-groups’, Psychological Science 14 (2006), pp. 847–53CrossRefGoogle Scholar and Harris, L. T. and Fiske, S. T., ‘Social Groups that Elicit Disgust are Differentially Processed in MPFC’, Scan 2 (2007), pp. 45–51Google ScholarPubMed.

²³ Adding to the worries about the dehumanizing stigma associated with disgust is that the emotion has been connected to dogmatism, see e.g. Russell, P. and Giner-Sorolla, R., ‘Social Justifications for Moral Emotions: When Reasons for Disgust are Less Elaborated than for Anger’, Emotion 11 (2011), pp. 637–46CrossRefGoogle Scholar.

²⁴ It is important to distinguish disgust from other related emotions like shame or guilt, since our arguments turn on features specific to this emotion. We are not making claims about any other emotions. Nor do we make any claim about the different ends that disgust's advocates have recommended it be used to achieve; we are arguing that in virtue of this particular emotion's nature, it is a bad social tool.

²⁵ Lane, K., Banaji, M., Nosek, B. and Greenwald, A., ‘Understanding and Using the Implicit Association Test: IV: Procedures and Validity’, Implicit Measures of Attitudes: Procedures and Controversies, ed. Wittenbrink, B. and Schwarz, N. (New York, 2007), pp. 59–102Google Scholar.

²⁶ Kelly, D., Faucher, L. and Machery, E., ‘Getting Rid of Racism: Assessing Three Proposals in Light of Psychological Evidence’, The Journal of Social Philosophy 41 (2010), pp. 293–322CrossRefGoogle Scholar.

²⁷ Kahan, ‘The Progressive Appropriation of Disgust’, p. 64, quoting from Miller, The Anatomy of Disgust, p. 36.

²⁸ Kahan, ‘The Progressive Appropriation of Disgust’, p. 69.

²⁹ Kahan, ‘The Progressive Appropriation of Disgust’, p. 64.

³⁰ Kahan, ‘The Progressive Appropriation of Disgust’, p. 64.

³¹ W. Miller, The Anatomy of Disgust, p. 197.

³² For a different take on the role of disgust in signalling and commitment, see Kelly, Yuck!, esp. chs. 3 and 4.

³³ In other words, here are two distinct claims that one could make about a hypothetical society devoid of disgust. The first is that the society would still perceive moral outrages, but would lack the resources needed to remark or react to them suitably; the society would be alert but disarmed, impotent. The second, stronger claim is that without the emotion of disgust, the society would not even be aware or alert to those transgressions; its members would not even be able to perceive those outrages as such in the first place, let alone respond to them with the passionate condemnation they deserve. We unpack the way Kahan makes the second kind of claim in the main text presently.

³⁴ Kahan, ‘The Progressive Appropriation of Disgust’, p. 63.

³⁵ Kahan, ‘The Progressive Appropriation of Disgust’, p. 66.

³⁶ Kahan, ‘The Progressive Appropriation of Disgust’, p. 67 (italics added).

³⁷ Kahan, ‘The Progressive Appropriation of Disgust’, p. 69.

³⁸ Kahan, ‘The Progressive Appropriation of Disgust’, p. 67.

³⁹ Kahan, ‘The Progressive Appropriation of Disgust’, p. 64.

⁴⁰ Kahan, ‘The Progressive Appropriation of Disgust’, p. 63 (italics added).

⁴¹ Adding to the trouble here is that a large number of cues that have nothing to do with highfaluting moral issues also activate disgust, namely those associated with poisons and parasites, and the emotion has a propensity to yield false negatives even in those primary domains. On the reasonable assumption that disgust in the face of these kinds of cues is irrelevant to moral justification, some independent criterion is needed to rule them out as well.

⁴² Kahan, ‘The Progressive Appropriation of Disgust’, p. 63.

⁴³ Of course: one might give a detailed, accurate explanation of the establishment and operation of the institution of slavery in North America without ever making the mistake of thinking that the explanation of the institution also justified the institution.

⁴⁴ Many thanks to those who gave us valuable feedback on early presentations of this material, including Mark Bernstein, Brian Besong, Mark Johnson, Leigh Raymond, Dan Smith and Laurel Weldon; Andreas De Block, Jan Heylen and the members of the philosophy departments at KU Leuven; the participants in the Evolution of Disgust conference at the Universität Bielefeld; and Thomas Pollett, Jan Verplaetse and the members of The Moral Brain research group at Ghent University.