McMahan's Time-Relative Account of Interests
A new guest essay published at utilitarianism.net
Jeff McMahan’s guest essay, The Time-Relative Account of Interests, has just been published to utilitarianism.net! To briefly introduce the topic:
The utilitarian goal of promoting everyone’s interests is complicated by the Parfitian view that one’s self-interest across time is a matter of degree (based on psychological connectedness) rather than all-or-nothing identity. This essay introduces and explores the Time-Relative Account of Interests, which uniquely captures key intuitions about the relative misfortune of death at different stages of life.
This account is (in my opinion) one of the most significant innovations of contemporary ethical theory, shedding light on vitally important “life and death” issues in applied ethics (such as abortion). So I’m very happy to be able to publish this insightful exploration of the topic by its leading proponent.
As McMahan explains his core view:
[T]he strength of a person’s interest at time t in having some benefit in the future, or avoiding some harm, is a function of two variables: (1) the magnitude of the benefit or harm at the time when it would occur and (2) the strength of the prudential unity relations [e.g. psychological connectedness] between the person at t and herself at the time the benefit or harm would occur.
The prudential unity relations normally weaken with the passage of time. That is, a person at t1 is normally less strongly psychologically connected and continuous with herself as she will be at a much later time, t3, than with herself as she will be at an earlier time, t2. Thus, her interest at t1 in having a benefit at t2 is normally stronger than her interest at t1 in having the same benefit at t3. We can refer to this understanding of interests as the “Time-Relative Account of Interests,” or TRAI.
Traditional (“life-comparative”) accounts of the harm of death implausibly imply that the worst time to die is immediately after you come into existence, as that deprives you of the greatest amount of future life. McMahan objects:
The life that an individual loses by dying shortly after beginning to exist is, as Parfit might have said, relevantly like the life of a different individual. Hence when an individual dies immediately or shortly after beginning to exist, that is relevantly like that individual’s never coming into existence at all…
[The TRAI] supports a permissive view of the morality of abortion, as it implies that death is not a significant misfortune for a fetus. If, as many people believe, we begin to exist before the fetal brain develops the capacity for consciousness, the death of a fetus before this point may not be a misfortune at all for that fetus, as no prudential unity relations would hold at all between the fetus and itself in the future. And if, as others believe, we begin to exist when, or even after, the capacity for consciousness arises, there would be psychological connections and psychological continuity of only negligible strength between the conscious fetus and itself in the future when it would be capable of having a substantial level of well-being. Fetuses, therefore, have either no interest in continuing to live or, later in the course of gestation, only a very weak interest in continuing to live. On this account, then, apart from any side effects involving the interests of others, the killing of a fetus frustrates at most only a very weak interest, and thus inflicts only a comparatively insignificant harm.
This incredibly rich essay goes on to explore complications involving pre-natal injury, non-identity and the “divergent lives problem”, the “no-difference view” in population ethics, the relative strengths of “narrow individual-affecting reasons” and other (e.g. impersonal) welfarist reasons, and how this differs between “harms” and “benefits”.
It’s an absolute must-read for anyone interested in ethical theory. Enjoy!