by Brian Tomasik
First published: 15 Nov. 2017; last update: 15 Nov. 2017


I this brief article, I defend negative utilitarianism against the charge that it overrides individual preferences. I suggest that the contrast between negative and non-negative flavors of utilitarianism can be seen as boiling down to the issue of interpersonal comparisons of utility. Since there's no non-arbitrary way to interpersonally compare utility, there's also no non-arbitrary basis for claiming that non-negative utilitarianism is more respectful to individuals' preferences than is negative utilitarianism.

The allegation

A common charge against negative utilitarianism is that it may contradict the preferences of the individuals whose interests it aims to consider. For example, suppose a person currently feels that his life is worth living and is glad to have been born. Negative utilitarianism might, depending on the extent of suffering in this person's life, say that this person's life has net negative value overall. Shouldn't we try to respect the wishes of agents, rather than forcing how we feel onto them?

We can problematize this allegation in a number of ways. For example, we might ask how to non-arbitrarily identify a person's true, idealized preferences at a given moment if those idealized preferences differ from that person's stated or revealed preferences. We might ask what to do in situations where the parts of a person's brain that control speech favor an action that other, less powerful parts of the person's brain disfavor (Tomasik "What ..."). However, in this piece I'll focus on one particular problem for the allegation that I think is most severe.

Interpersonal comparisons of utility

Imagine that the entire history of the universe contained only a single individual for a brief period. If that individual prefers X over Y, then it seems plausible that it's morally better for X to be the case than Y.

However, things become tricky as soon as we have more than one individual with conflicting preferences. If Alice prefers X to Y while Bob prefers Y to X, is it morally better for X or Y to be the case? There's no obvious answer. In order to choose between X and Y, we as moral arbiters have to decide if we care more about Alice's preference or Bob's preference. This introduces inevitable arbitrariness into our moral views.

Suppose we think Alice's preference is more weighty than Bob's and favor outcome X. Have we thereby disrespected Bob's preferences about what he prefers? Sort of, but there was nothing we could have done not to disrespect someone's preferences in this case.

Application to negative utilitarianism

Suppose the universe contains only Alice and Bob. Bob is glad to exist and considers his life to have net positive welfare. Alice despises her life and wishes she hadn't been born. Would it be better if neither Alice nor Bob existed? Or is it better that they exist?

As we saw above, there's no "right way" to make this judgment call. If we favor nonexistence, we violate Bob's preference (or, at least, what would have been Bob's preference had he existed). If we favor existence, we violate Alice's preference.

A negative utilitarian can be seen as someone who, when making these arbitrary interpersonal comparisons of utility, tends to take preferences not to exist or to avoid harm very seriously. Meanwhile, a more positive utilitarian can be seen as someone who takes preferences to exist or to have pleasurable experiences very seriously.

Loosely, we could say that negative utilitarians "give more weight" to anti-suffering preferences in interpersonal comparisons than non-negative utilitarians do. But such a statement shouldn't be interpreted as implying that there's any non-arbitrary baseline of how much moral weight different preferences should get (see Knutsson 2016). We could just as well say that non-negative utilitarians "give more weight" to pro-happiness preferences.

Inter-person-moment comparisons of utility

The classic problem of interpersonal comparisons of utility assumes that each individual has a single utility function. But in fact, people's preferences change over the years, and even from minute to minute. So there's also a problem of intrapersonal comparisons of utility across time. If we think of each moment of an individual as a different "person-moment", then we could call this the problem of inter-person-moment comparisons of utility.

Bob may affirm his own existence at time 1 but, due to unbearable suffering, wish he didn't exist at time 2. If we're faced with the choice of either creating Bob's existence or preventing it, which is the right choice? There's no clear answer. Either way, we'll contravene the wishes of Bob-at-time-1 or Bob-at-time-2. (Actually, if Bob never exists, we never contravene his wishes, so we could also argue for nonexistence on those grounds.)

What kind of negative utilitarianism is this?

The arbitrariness of interpersonal and inter-person-moment comparisons of utility is perhaps my favorite way to think about negative utilitarianism. It's not a moral tragedy if someone experiences a pinprick but still, during that moment, is overall happy to be alive. The moral force of negative utilitarianism comes from instances of extreme suffering that, to the person afflicted, feel so bad that the person wishes the world had never existed. These are the kinds of intense preferences where it feels genuinely morally unclear how to weigh these preferences against the pro-existence preferences of other people or other person-moments.

An approach to interpersonal/inter-person-moment comparison that always respects nonexistence preferences over existence preferences, and always respects preferences not to have some collection of experiences over preferences to have some collection of experiences, is what I've elsewhere called consent-based negative utilitarianism. For example:

  • Suppose you're considering whether to create 100 new people. 99 of the people would be glad to exist, while 1 would wish not to have existed. Consent-based negative utilitarianism favors not creating this population because one of the members has not consented to being born. The anti-existence preference is "given more weight" in interpersonal utility comparisons than the pro-existence preferences.
  • Suppose a person agrees to undergo an excruciating experience for later reward. During 9.5 out of the 10 minutes of the process, the person agrees with the decision to experience pain because the emotional cost is compensated by the later reward. However, during the worst 0.5 minutes of the process, the person is overwhelmed by agony and terror and wishes that he had never signed up for this tradeoff. Because the person doesn't consent to the tradeoff during those 0.5 minutes, consent-based negative utilitarianism disfavors this pain-for-pleasure deal. The person-moments in unbearable agony take precedence over the non-agonized person-moments when doing inter-person-moment utility comparisons.

In cases where both available options would cause some amount of non-consensual suffering, consent-based negative utilitarianism favors the action that causes fewer person-moments to non-consensually suffer, causes less intense non-consensual suffering, and so on.

We can also derive a weaker form of negative utilitarianism than full consent-based negative utilitarianism by generally giving precedence to anti-existence and anti-suffering preferences while sometimes letting pro-existence and pro-happiness preferences win out.


I first made an argument along these lines in a 2013 online discussion. Simon Knutsson makes essentially the same point, spelled out in more detail, in "What Is the Difference Between Weak Negative and Non-Negative Ethical Views?"