How Long Ought We To Live: The Ethics of Life Extension

In the future we will have technology capable of extending human
lifespans beyond their current maximums, making the issue of longer
lives a pressing one for the species. Some have claimed that humans
living longer lives is not self-evidently a good thing. Others have argued
that developing technologies to radically extend the normal human
lifespan would be wrong because the negative consequences for societies
and for future generations would outweigh the benefits of having the
technology. I argue in this thesis that developing life extending
technology would be permissible.

I proceed first by examining two prominent sets of arguments
from Leon Kass (2004) and Bernard Williams (1973) that the personal
desire for a profoundly longer life is an irrational one. Their arguments
attempt to demonstrate that living too long would be antithetical to a
meaningful and attractive existence for an individual. I closely analyse
both Kass’s and Williams’s arguments and ultimately find that they do
not demonstrate that the desire for profound personal survival is
irrational or that survival is necessarily a bad thing for the individual.

Building on this conclusion, I argue that life extension might be a
good thing by showing why death can be a harm to the one who dies and
why a longer life is better than a shorter one, other things being equal. I do this first by defending and modifying views about why death can be
bad for the one who dies, such as Nagel’s ‘deprivation account’ and
Williams’s account of the importance of ‘categorical desires’. I also
defend a ‘non-episodic’ view of personal experience and desire
satisfaction against the Epicurean ‘episodic’ view of personal time to
reveal why a longer life, all else equal, is better than a shorter one.

If survival is not necessarily a bad thing for the individual and a
premature death can be a harm, then life extension—as far as the
individual is concerned—must be a good thing. I assume these conclusions as I proceed to argue that developing life extending
technology would be permissible. Focusing exclusively on an argument
from Peter Singer (1991) that developing a life extension drug that
doubled the average human lifespan to 150 years would be
impermissible—because doing so would bring about a future world with
lower total and average wellbeing—I highlight problems with the moral
principles that guide Singer to his conclusion and propose a more
acceptable version of average utilitarianism, which, if applied to the case
of developing a life extension drug, demonstrates that developing a drug
that doubled the human lifespan would result in an outcome with higher
average happiness per person, making the decision to develop life
extension permissible on a consequentialist view.

Proceeding forward on the assumption that developing life
extending technology would be permissible, I challenge the argument
that the only just distribution of life extending technology is to provide
everyone equal access. I present the case that life extending technology
would be most fairly distributed under a certain interpretation of the
Rawlsian difference principle of resource distribution in a way that gave
priority to those least advantaged with regard to life expectancy. My
defence of this prioritarian version of the difference principle is also
compatible with the view that older persons can sometimes deserve
priority for life extending interventions over younger persons, thus
challenging the ‘fair innings’ intuition that we ought to, in principle, give
priority for life extension interventions to younger persons over older
persons when in competition for these resources.

The conclusions of this thesis reveal some misconceptions about
the value of longer lives for individuals and of developing life extending technology. What we need is more detailed philosophical analysis of the
issues relating to humans beings living longer lifespans and the
consequences of having technology capable of radically extending
human lives than has been devoted to these issues up to this point.