by Brandon Yip, assistant professor of philosophy, psyche.co
‘Disgusting’ and similar words are flung across political divides quite often today. For example, the US president Donald Trump has used the word to describe his political opponents, journalists and others. And many have voiced disgust at the president’s own behaviours. For instance, after viewing Trump’s altercation with the Ukrainian president Volodymyr Zelenskyy during a press conference in 2025, the author David Brooks described feeling ‘nauseated, just nauseated’. In politics and beyond, expressing disgust is a common response to actions that one finds deeply objectionable, such as racist rhetoric, acts of sexual abuse or policies that harm vulnerable people.
Rather than see expressions like these as merely rhetorical, many philosophers and psychologists argue that moral disgust is a distinct and significant kind of moral response. The distinction between moral disgust and regular disgust lies in the way their objects are experienced by the disgusted person. People feel regular disgust in response to the spread of filth, which motivates physical avoidance and cleansing. The stench of urine on a train, for example, provokes this kind of disgust. When people feel moral disgust, it’s as if they are experiencing a sort of moral pollution, which motivates them to socially avoid and exclude the target of the disgust. Betrayal and exploitation, for example, often provoke moral disgust, but not regular disgust.
Many scholars believe that disgust operates based on simplistic and unreliable heuristics. For example, in his book Yuck!: The Nature and Moral Significance of Disgust (2011), the philosopher Daniel Kelly argues that disgust is an evolutionarily old mechanism that protected humans from poisons and parasites – and so it operates on a ‘hair trigger’ that is prone to generate false positives. Kelly thinks that, since moral disgust grew out of regular disgust, it is similarly unreliable when it comes to moral matters. Just as you can find some physical thing disgusting (say, a certain kind of cheese) when it’s actually harmless, you might automatically find some behaviours morally disgusting that, on reflection, aren’t so bad.
Now, some of Kelly’s premises can be challenged: there is evidence that our emotional systems are intelligent and adaptable. Rather than just recapitulating ancient functions, our emotions contain updating mechanisms that enable them to respond to new physical and social challenges. Furthermore, even regular disgust is flexible and remarkably sensitive to context. For example, whether you find saliva disgusting depends a lot on whether it comes from your lover or a total stranger.
Some have argued that, far from being unreliable, moral disgust plays an invaluable role in moral judgment. In Leon Kass’s classic essay ‘The Wisdom of Repugnance’ (1997), he claims that people’s disgust towards human cloning gives us some reason to avoid that practice, warning us ‘not to transgress what is unspeakably profound’. In this decadent age, Kass says, ‘repugnance may be the only voice left that speaks up to defend the central core of our humanity.’
So, is feeling morally disgusted by an act or a practice something that we should take seriously as a sign that it is morally problematic? To answer this, we need to first get clear on why people feel moral disgust – what exactly it alerts us to.
Contemporary philosophers have offered various explanations of what moral disgust does, though each of these has limitations. In Alexandra Plakias’s account, for example, moral disgust is a response to behaviours that are socially contagious: norm-violating behaviours, such as acts of physical violence, that might spread through a population if left unchecked. This is a compelling idea, but upon further examination, the relationship between socially contagious behaviours and moral disgust appears to be tenuous. Many norm violations that could be socially contagious – such as stealing office supplies or not declaring tips as taxable income – don’t tend to strike people as morally disgusting.
Presenting a different view of moral disgust, Victor Kumar suggests that it’s a response to behaviours that undermine relations of trust and reciprocity. He is certainly right that behaviours that undermine cooperative relations, such as betraying one’s compatriots or unfairly dividing rewards, are often seen as morally disgusting. Yet there are also many other acts that people find morally disgusting – such as cannibalism, or incest among consenting adults – that do not involve a failure of reciprocity.
I believe that John Kekes was on the right path with a suggestion he put forth in the 1990s. Kekes proposed that moral disgust enforces moral taboos – prohibitions against the kinds of actions that endanger the very possibility of civilised life. These violations supposedly ‘threaten to bring about a form of life in which moral considerations have no foothold.’ This seems somewhat overblown: after all, civilisations have repeatedly survived the violation of moral taboos. But perhaps what moral disgust does is guard against the collapse of particular forms of rule-structured life.
To see what I mean, consider the relationship between our personal behaviours and the social worlds that we inhabit. A social world is structured by rules and norms that people have internalised and adopted. Tamar Schapiro points out that these normative orders are sustained by individuals’ compliance with the rules. A judge who continues to follow legal procedure – even when they could choose to act corruptly – helps to sustain the larger normative structure that gives the judge’s actions legitimacy.
If norm compliance keeps important social structures intact, then perhaps certain actions can undermine them. Imagine that you are trying to play soccer with players who are randomly picking up the ball and throwing it around. Such behaviour not only violates the rules of the game, it undermines the game itself. Something analogous happens in typical cases of moral disgust, where the stakes are higher. In explaining his nausea at seeing Trump behave ‘vilely’ toward Zelenskyy and US allies, for example, Brooks suggested that Trump was unravelling a benign, US-centred international order and replacing it with one where ‘might makes right’. Let’s call actions that undermine a social order socially corrosive.
My proposal, then, is this: moral disgust is a response to behaviour that is socially corrosive. More precisely, when some behaviour undermines a set of moral norms that a person is attuned to, they feel morally disgusted.
The moral norms you are attuned to are those that appear to you to impose genuine constraints on behaviour. Your attunement to these norms might be strong and overt – you might explicitly endorse your culture’s norms against using corporal punishment on children, for example. Or, your attunement might be merely implicit. If you grew up in an Islamic culture that sees eating pork as morally disgusting, but then you left Islam, you might still continue to experience the pork prohibition as having some force. People can also become attuned to new norms. An adult Muslim convert – or a vegan – could come to acquire moral disgust towards pork-eating.
When I suggest that morally disgusting actions undermine some social order, I mean that they threaten to stop a community from operating with some set of moral norms. For example, if a political leader engages in corruption or an employer openly flirts with his employees, then the norms that govern that society or that workplace will be undermined as long as such behaviour goes unchecked. This possibility is more serious than just contagious norm-violation; it is not simply that more corruption or more creepy flirting is forthcoming. It’s that the rule of law or respectful workplace interactions become tenuous altogether. Moral disgust alerts us to the fact that certain behaviours might corrode the moral norms that we care about, and it motivates us to sanction or exclude those who behave in those ways.
With this in mind, it is worth returning to Kass’s article about cloning and disgust. He notes that human beings have ‘systems of identity and relationship on the bases of Ö deep natural facts of begetting,’ and suggests that cloning would confound ‘all normal understandings of father, mother, sibling, grandparent, etc.’ To Kass, then, what is problematic is not just the wrongness of cloning in itself or its mere proliferation. Rather, accepting cloning would unravel a set of norms governing human relations.
Could cloning really undermine all that? It’s not as implausible as it might seem. Already, the norms surrounding sex and the family have undergone radical transformation over the past century. Behaviours once seen by many as morally disgusting, such as premarital sex or homosexuality, are now widely seen as morally acceptable. This has produced profound changes in the meaning of marriage and sex. Even if we consider these changes liberating – welcome alterations to an overly constricting social order – these examples show how it’s plausible that a broader set of moral norms (such as those structuring families) is susceptible to change once key norms (such as those governing procreation or sex) become undone.
Clearly, we should not uncritically endorse the deliverances of moral disgust. One may, for example, decide that the familial structure that Kass protects is an unjust and patriarchal one. The norms we are attuned to are a mixed bag that includes both aspirational ideals that bend towards justice, as well as the nastier parts of our cultures.
Yet it is still worth listening to our moral guts – carefully. Moral disgust sometimes provides a signal that something is deeply wrong, even when one’s capacity for moral reasoning has been compromised. Ditte Marie Munch-Jurisic has noted, for example, that the perpetrators of heinous crimes often react with disgust toward their own actions. Under the Nazi regime, some soldiers and citizens experienced sheer revulsion in carrying out their role in the Holocaust. They suppressed this revulsion with reasons provided by the ideological narratives of the Nazi regime. Similarly, Miranda Fricker has shown that injustice sometimes makes it hard to understand the conditions of oppression. For example, prior to acquiring the concept of sexual harassment, many women struggled to articulate the problematic nature of men’s inappropriate advances. But they were morally disgusted by such behaviour, even before they could fully explain why it was wrong – including how it undermined norms of equal respect for men and women.
If there is a wisdom in moral disgust, then, it is an ambivalent one that we should not always heed, yet cannot simply ignore. Unfortunately, there isn’t a simple formula to tell us whether moral disgust is highlighting something important or leading us astray. When we feel or encounter moral revulsion, we should neither dismiss it as mere primitive reaction nor treat the emotion as having an infallible moral authority. Instead, we ought to pause and reflect on what we are actually responding to. We should try to articulate the normative order that our revulsion is guarding – and then ask ourselves whether or not we have good reasons to cherish it.
About the author; Brandon Yip is assistant professor of philosophy and Lee Kong Chian Fellow at Singapore Management University. His research covers a range of interconnected questions in moral psychology, epistemology, and meta-ethics, with an eye to how these connect with broader questions in social philosophy.
Keywords; emotions, psychology
