'Novels can do it much better.' (Screen Archives/Getty Images)

September 22, 2023   6 mins

Imagine that a philosophy professor is invited onto a podcast. The hosts ask him to describe a thought experiment he finds interesting or provoking. He decides to pick a scenario in which an adult male has sex with a “willing” 12-year-old girl, before saying that the man in his example would not necessarily be at fault. It would, he says, depend on whatever accompanying harm was caused to the child, but there are some situations in which the sexual activity would be harmless. Would the professor’s proffering of such a thought experiment be morally wrong?

It seems a lot of people think so — for of course this particular case isn’t just hypothetical. In January last year, Professor Stephen Kershnar was invited on to the podcast Brain In A Vat to discuss the topic of “Sexual Taboos”. After his choice of thought experiment was excerpted and tweeted out by Libs of TikTok, things escalated quickly. Conservative websites pounced. A student at Kershnar’s university, SUNY Fredonia, started a petition demanding he be fired. The university president directed police to search Kershnar’s computer, took him out of teaching on the grounds of student protection, and put him under investigation. Though he kept his paycheck, he has since been barred from teaching. According to the New York Times this week, he is now suing his employer.

In truth, Kershnar hardly offered a thought experiment at all. Compared with the most elaborate of philosophers’ constructions — see Judith Jarvis Thomson’s baroque image, offered in defence of abortion, of waking up to find yourself non-consensually hooked up to an unconscious violinist, physically dependent on your circulatory system to recover from a poisoning — it was barely more than a sketch. But failure to meet the normal standards of thought experiments is not what people objected to here.

One typical insinuation of Kershnar’s critics seemed to be that, by offering such an argument, he must have been indulging in a case of special pleading. The assumption was that, by his choice of example, and, indeed, by the book he wrote beforehand partly defending the same sort of  conclusions, he inadvertently betrayed his own paedophilic sexual predilections, thereby removing any claim to intellectual authority. (He strongly denies this.)

But other explanations are also available, embedded within the peculiar culture of academic philosophy. There is, for instance, an established tradition within applied ethics of coming up with counterintuitive conclusions. After all, there’s no fun or kudos in saying the same thing as everyone else. One approach is to demonstrate to readers that, given ethical principles or values to which they are already committed, surprising and perhaps even shocking consequences seem to follow. Some dispassionate types just find this sort of thing cool and edgy, independent of the emotional impact generated for others. Kershnar himself seems to be a big fan of the tactic. His published work includes moral defences of torture, slavery, violent sexual fantasies, anti-immigration policies, faking orgasms, only dating Asians, and discounting women’s applications for jobs in philosophy departments.

Occasionally in philosophy, some famous ethicist or other is criticised for failing to live up to his own favoured principles in private life. In this particular case, you rather hope Kershnar doesn’t try too hard. Looking at the evidence available, though, it seems mostly likely that he’s just a professional contrarian. In the legal case against his university, his lawyers quote a student as saying of the professor “it was almost impossible to tell what he actually believed and what he didn’t”. I forced myself to read one of his background articles about paedophilia, and found the relentless tone-deaf logic-chopping almost unbearable in the context of the prurient subject matter. Still, for all I know, the interest is entirely academic. Philosophers are, after all, quite strange.

As the not-particularly-popular saying goes: “one person’s modus ponens is another’s modus tollens”. That is: when faced with an apparently intolerable conclusion stemming from an apparently sound argument, you can either accept the conclusion, or work harder to find out what was wrong with your premises in the first place. Some thinkers fight much harder than Kershnar to reject the disturbing conclusions that seem to follow from relatively unexceptionable premises. Oxford philosopher Derek Parfit, for instance, devoted an enormous amount of energy trying to avoid what he called “The Repugnant Conclusion” in population ethics. This says, roughly, that the existence of a very large population with very low average happiness per person is preferable to that of a small population with very high average happiness. In the end though, by his own admission, Parfit couldn’t dislodge it — thereby handing a gold-plated excuse to leaders of large countries with failing economies to increase the birth-rate.

Others just go with the rational flow, coming to fully endorse value judgements that nearly everyone else rejects. For instance, as is well-known, Peter Singer holds that in certain circumstances, killing disabled babies would be preferable to killing animals. Elizabeth Barnes thinks there would be “nothing intrinsically wrong” with “a mechanism that allows non-disabled people to become disabled if they wish”. Julian Savulescu and others argue that there are “equity-based reasons” to use drugs to keep “non-binary adults” in a permanent pre-pubertal state, so that the development of secondary sex characteristics is permanently prevented. Whatever the ultimate success or failure of these arguments, there is probably not a single grotesque behaviour in history that couldn’t be justified by some philosopher somewhere, playing around with a highly unlikely-but-still-possible scenario in which the behaviour is present, but where “harm” is magically subtracted and “consent” or “benefit” added.

The most basic use of a thought experiment in ethics presents us with a particular hypothetical case and asks us what our “pre-theoretical intuitions” tell us about it — which might sound pleasingly technical to the uninitiated, but could just as well be reframed as asking what feelings you are now getting in your water. Confronted with this scenario, it asks: do you feel such-and-such would be right / wrong / good / bad / fair / unfair? Whatever you say in response to the imaginary version, it’s assumed you would also say the same towards the equivalent real one.

Then, depending on the case, something more complex might be attempted: for instance, an analogy might be made with some other more mundane and everyday case, to suggest your intuitions should be the same there too. This is effectively what Thomson’s violinist experiment does. If your intuitions tell you that it would not be wrong to detach yourself from an unwanted violinist in the circumstances she outlines, even if this resulted in the violinist’s death, then — since the situations are supposed to be relevantly similar — you ultimately should conclude the same in the case of an unwanted foetus. (Thomson has a further explanation of what the common factor allegedly is.)

Yet if I were suddenly plunged, for real, into a situation involving an unconscious violinist being plumbed into my or someone else’s circulatory system, I’d be in a very different sort of world from this one — quite possibly, a world directed by David Cronenberg. Who knows what other weird stuff would be going on there? And who knows how I’d react to it, if so? The question arises of why I should take my responses to this crazy tale to be indicative of anything at all.

Kershnar’s thought experiment is different because it describes a scenario that nearly everyone would intuitively reject as wrong. Still, when you look at his published background reasoning about the supposed permissibility of hypothetical instances of “adult-child sex”, it also involves appealing to intuitions about totally anachronistic scenarios. For instance, he discusses a situation where there exist children who are “precocious and fully grasp the different dimensions of sex like some precocious children can grasp the different dimensions of music and mathematics” (and moreover where, presumably. we could somehow reliably test for this understanding). The relevance to the actual world, where children are not actually precocious in this way and sex is nothing relevantly like mathematics or music, is totally obscure.

In any case, real-life events — unlike thought experiments — aren’t just stripped-down stories, pruned of distracting ephemera to get to the bits the philosopher really wants you to notice. They come thicketed with endless detail to be noticed even years afterwards. And with moral reactions, it’s the details that matter. Not just details about who did what to whom; but also why, and how much did it hurt, and who did it help, and what did all parties think was going on, and what exculpatory factors existed beforehand, and what happened afterwards; and how did all these factors interact in this particular case? Novels can do this stuff much better. Lolita can tell you what is wrong with paedophilia much more powerfully than any dry fictional construct from a bloodless academic.

None of this is to suggest that Kershnar should have been punished as he was. Distasteful as his general approach is, arguing for the permissibility of doing something is not the same thing as doing that thing yourself. In a society that values freedom of thought, we have to fight hard to maintain this distinction, or else the whole enterprise of arguing about ethics collapses completely. Still, perhaps ironically, what happened to Kershnar’s podcast once the internet got hold of a small part of it tells us something instructive about the problem with ethical thought experiments in general. A snapshot was taken of a multifaceted situation; any relevant or complicating context or background was removed; and it was flung like red meat towards readers for a satisfyingly outraged moral reaction. If we want to understand complex real-world ethical issues, we should probably try to avoid this sort of thing.

Kathleen Stock is an UnHerd columnist and a co-director of The Lesbian Project.