Should You Choose to Live Forever? is one of the newest entries in Routledge’s excellent “Little Debates about Big Questions” series, and it’s the best one I’ve read. Every book in the series has three parts. In the first, each author makes their positive arguments for their favored positions. Here Stephen Cave and John Martin Fischer start by offering modified, synthesized, versions of their respective “immortality curmudgeon” and “immortality optimist” positions, both having significantly shaped the immortality literature (see, for instance, Fischer 2009, 2019, and Cave 2017). This is followed by a second section where each replies to the other’s positive arguments, allowing them to move beyond their original arguments. Finally, in the third section, each very briefly replies to the other’s initial reply.
The end product is a book that’s both a comprehensive overview of two seminal figures’ positions on immortality and a debate book that actually furthers the debate on the desirability or undesirability of immortality. Notably, the progress would be hard to replicate without Fischer and Cave being in direct dialogue with one another.
The first chapter begins with Cave’s arguments against the desirability of immortality, and some necessary distinctions. Cave distinguishes between moderate life extension (120–160 years), radical life extension (halting aging but retaining vulnerability to accidents), contingent immortality (invulnerable to aging or accidental death, but able to die if and when one wants), and true immortality (unable to die under any circumstances).
The general question of whether one should choose to live forever is thus broken down into a set of interrelated questions about whether immortality, in any of these senses, would be morally or prudentially desirable under any conditions. The tricky philosophical questions concern whether certain kinds of immortality would be worth pursuing under closer to optimal conditions. Cave is skeptical. Assuming that personal (and perhaps practical) identity is maintained, Cave offers various arguments against immortality being prudentially desirable. Inspired by Williams (1973), Cave believes that human persons have a finite number of experiences or activities that they could find pleasurable before indefinite repetition would rob the experience or activity of the ability to produce any joy. Relatedly, enough time would force people into a “consciousness of the dull” that would result in extreme, alienating, and interminable boredom (25–26).
The potential downsides don’t end there. Drawing from Borges (1970) as well, Cave argues that immortality, or at least true immortality, would result in every individual doing everything, which would cause people to lose what distinguishes them from others and so lose meaningfulness in their lives. As Cave sees it, such immortals face a dilemma. They can either stick to a narrow range of activities (and so become interminably bored) or can continually do new things to enjoy life but then sacrifice meaningfulness in life (30). A final prudential concern is the so-called procrastination problem. If we really lived forever, there wouldn’t be temporal constraints imposed on us by death, which would make time have no value, and temporal scarcity wouldn’t galvanize us into action (32).
These potential prudential problems apply most forcefully to true immortality. According to Cave, however, there are also moral problems with immortality, which forcefully apply to the more moderate forms of immortality as well. The first is the clear risk of overpopulation and the well-known moral and practical problems with trying to impose large-scale measures for population control (40). Just think of China’s disastrous One-Child policy. Social justice issues would be inextricably tied to immortality as well. As with all new technologies, it would first and most readily be available to the wealthiest people. This could widen the inequality gap, both in terms of monetary wealth and time, which is, itself, valuable. The case against immortality is strong, Cave believes, and we shouldn’t want anything beyond moderate life extension.
At this point, John Martin Fischer proceeds to make an even more forceful case in favor of the desirability of immortality, at least under certain conditions. Drawing on Nagel (1986, 224), Fischer argues that if living one more good week is prudent, then by extension, making this choice indefinitely should also be prudent (60). Now, crucially, one has an “out” in this thought experiment, always having the option to forgo continued life. Fischer acknowledges that choosing true immortality may be a choice that is too prudentially risky, even if there are some truly immortal lives that are infinitely good for the beings living them (64). Fischer’s focus, then, is on beings who live indefinitely or even forever through radical life extension. Could any of those lives be worth pursuing? “Yes,” Fischer argues.
Fischer’s main arguments in this section are negative in the sense that he defends the desirability of immortality against the strongest objections in the literature. This makes sense, as the pro-immortality position is in many ways the default one. If some finite life can be good, then it seems prima facie plausible that indefinite extension of good life would also be good. Most people believe that they are, in fact, immortal and expect to live an infinitely good afterlife. Arguments for surprising conclusions are the ones seen in need of defense, and so the literature contains a greater number of arguments against the desirability of immortality than for it.
First up is the issue of personal identity. It’s not clear that immortality is even possible if people’s memories, character traits, dispositions, and so on continue indefinitely to change over time. Enough small changes would result in drastically large changes, and, at some point, the original person might literally cease to exist. Fischer outlines two views and argues that, on either, it’s possible to live forever while maintaining one’s identity. On one view, a sufficient condition for maintaining personal identity is the overlapping chain of memories, values, and other potential fundamental elements of our identity (74–78). On the other view, there is a basic, irreducible self (such as a Cartesian mental substance) that is the subject of consciousness. This subject could even have completely different memories from their actual memories without the interlocking chain. Either way, Fischer argues, identity could be maintained over an immortal life (77).
Fischer moves on to concerns about motivational inertia. The worry is that if there is an infinite (or even very large) amount of time available to pursue one’s goals, then people’s dispositions to procrastinate would be exacerbated. In framing the objection, Fischer asks what “motivation would we have to attempt to start and build relationships and to pursue projects in a timely way?” (78). Part of the answer, he argues, lies in people’s temporal bias. Humans prefer prudentially bad things later rather than sooner and prefer to have prudential goods sooner rather than later (79–80). They want good things to be in their future and bad things to be in their past. This alone can motivate people to act, even if they technically could wait without detracting from their total well-being. Moreover, and just as importantly, beings with radically extended lives cannot be certain that they will live forever, even if they in fact will. As Fischer understands radically extended lives, one can still die from accidents, and their expected lifespan would be around 6,000 years (66). But even in Cave’s sense of the term, the point still stands. Epistemic uncertainty about whether one will, in fact, live forever means that temporal scarcity remains a viable possibility and so should be factored into one’s deliberation about how to use one’s time, a point that Cave himself recognizes. This can, presumably, motivate people to act. Maybe I’ll live forever, but I’m not sure, and so I should probably write that book on death sooner rather than later.
At this point, Fischer focuses his discussion on the narrative structure of immortal lives (83–85). One objection is that immortal life would lack narrative structure, and so narrative value. The idea behind narrative value is that just like a good story has a beginning, middle, and end, so too does a good life. Immortal lives, however, lack the crucial ending. Yet Fischer convincingly argues that there can be narratives within immortal lives, and an infinite life could be constructed of such narratives, allowing them to have narrative value.
Along similar lines, one might worry that an immortal life would lack typically human life stages. So, it’s not just that they lack an end, but that they would lack the normal spans for some crucial stages, such as the period of adulthood between being a young adult and being a middle-aged person. The concern is that this difference would be so drastic as to prevent such life from being recognizably human. For his part, Fischer points out that our life spans have already increased a noticeable amount, while humans have maintained an ability to adapt to that, recognizing their humanness throughout the change (87–88). It’s also not clear why we should care about the lives being recognizably human at all as opposed to simply good for us. I, and it seems Fischer, would certainly prefer a life that is not recognizably human (whatever that means) if it’s longer and better for me than a life that is recognizably human that is also shorter and less good.
In the final section of Part One, Fischer gives his response to the concerns about boredom inspired by Williams. He makes, in my view, a near-decisive case that immortality wouldn’t necessarily result in interminable boredom, which is the only kind that threatens the desirability of immortality. Fischer distinguishes between temporary boredom and chronic and severe boredom (hyperboredom), arguing that the latter can be staved off by engaging in activities that will generate indefinitely repeatable pleasures, pursuing meaningful projects, and doing so via an immersive (to be fully present) rather than an extractive (concerned with getting something out of pursuits) approach to experience (95–103).
Part Two begins with Cave’s first reply to Fischer, much of which focuses on the practical. Cave identifies practical challenges to creating a world in which even radically extended lives could be worth pursuing. As a prime example, suicide to avoid interminable boredom might be considered immoral, and it will often be imprudent (or, really, perhaps just too risky) because there’s often a large enough chance that one will once again find joy in life (117). Death, given deprivationism, potentially becomes much worse for the one who dies, as it can deprive people of far more potential good. At the same time, without a sense of urgency generated by what is now a normal life span, people might become complacent with their day-to-day goods, failing to optimize value over their radically extended life (121–122). Appealing to the case of a real-life opera singer friend, Cave argues that humans would eventually become bored with immersive tasks in a radically extended life (123–124). Given the series of supposedly unfeasible conditions necessary for immortality to be desirable, Cave argues that it wouldn’t be desirable in the relevant practical sense.
In his reply, Fischer drills down to the locus of disagreement between him and Cave. While he agrees that choosing true immortality would likely be too risky, he argues that radical life extension under favorable conditions is a worthy choice, and he remains at least somewhat hopeful, although concerned, about the attainability of sufficiently favorable conditions. There is also a meta-disagreement, of sorts, about the value of thinking through the desirability of potentially unfeasible options.
Granting that not every kind of activity would remain interesting forever, Fischer argues that some intellectual activities and some simple ones (e.g. drinking, watching sunsets) contain enough variation that, when distributed properly, are reliable and repeatedly engaging (137).
Fischer then moves on to the moral questions. Here, he seems to agree with Cave about the moral risks created by radical life extension yet remains an “optimistic realist” about meeting those challenges (which still allows that humans are more likely than not to fail to meet those challenges). Still, overpopulation could be addressed with various equalizing measures of population control, such as voluntary abstention from procreation, lotteries for having children, and so on. Inequitable access to life extension should be addressed by working towards “eliminating unfair and differential access to health care in general” (153). Perhaps most interestingly, Fischer rejects the idea that we could have an obligation to continue to procreate, which is a central focus of Cave’s final reply in the book.
In Part Three, Cave’s final reply turns into a chapter about population ethics. There’s cultural and temporal variability of intuitions about obligations to have children, and Cave believes that we can have obligations to merely possible future generations. His argument appeals to a symmetry between obligations to refrain from creating bad lives and obligations to create good lives. Fischer, in arguing that we have no obligations to a “merely possible person,” seems to open himself up to difficulties in explaining how we could maintain an obligation to refrain from creating an overall bad life (169). This is indeed a tricky issue, but it’s one where I believe a clear response can be given. In creating bad lives, one harms a being with moral status, whereas one doesn’t by failing to create good lives. In failing to create good lives, one either doesn’t harm anyone at all or harms beings who never were, aren’t, and never will have moral status. Surely that is a morally relevant difference, and it can explain Fischer’s intuitive judgments about this procreation asymmetry.
Another worry is that Fischer’s commitments seemingly imply that there is no moral reason to wait to conceive a child if a future, different child would be much better off than the (still overall good) child that would be conceived in the immediate future. Again, I believe Fischer has good responses available to him. He could, for instance, agree that there ismoral reason to wait to have the happier child, while denying there is an obligation to wait for a variety of reasons, including bodily autonomy. He could also just accept this implication. As Boonin (2014: 198–205) has pointed out, if it’s permissible to have no child instead of a happy child, then surely, it’s also permissible to have an overall happy child instead of the happiest possible child.
Fischer uses his final reply to simultaneously summarize his arguments throughout the book and further refine his core arguments. Even in this short section, progress is made. One thing that comes out is the degree of agreement between Cave and Fischer. Most notably, there is a large overlap about the political and social conditions under which radical life extension, at least, would be desirable. With respect to these issues, the disagreement seems to be primarily non-moral and concerns how realistic a goal such conditions would be, as well as the value of thinking through such conditions. What follows are further clarificatory remarks about the role of time bias in helping people maximize value within finite periods of infinite lives, a fascinating discussion about whether Buddhism is a pessimistic doctrine (and whether its meditative practices could help people get through otherwise bad periods of immortal life), a survey of social changes that would be desirable means to optimal conditions for life extension, and his final word on how similar our life stages would have to be in a radically extended life to be worthy of our desire.
This book is essential reading for a number of reasons. Its extended dialogue format gives readers a clearer picture of how Fischer’s and Cave’s views relate to one another (both in terms of overlap and fundamental areas of disagreement), as well as the best reasons for and against each position. For scholars, this leaves fewer questions unanswered than just reading their solo works in isolation. For students, it serves as an ideal model of philosophical dialogue. It helped my students see clearly what is at stake in each debate and identify their informed opinions on the topic. This is, in part, because it’s so accessible and well-structured (each chapter has its own breakdown of contents and summary at the end). The book serves both as an ideal introduction to the literature for a layperson and as the most up-to-date version of Fischer’s and Cave’s positions. I highly recommend it for anyone working on or interested in philosophical issues related to immortality. As Cave and Fischer show, this includes (or should include) just about everyone.
ACKNOWLEDGMENTS
I would like to thank Jeff McMahan and Julia Knight for comments on an earlier draft of this review.
REFERENCES
Boonin, David. The Non-Identity Problem and the Ethics of Future People. Oxford University Press, 2014.
Borges, Jorge Luis. “The Immortal”, in Labyrinths: Selected Stories and Other Writings. Penguin, 1970.
Cave, Stephen. Immortality. Skyhorse, 2017.
Cave, Stephen. Immortality: The Quest to Live Forever and How it Drives Civilization. Skyhorse, 2017.
Cave, Stephen; Fischer, John Martin. Should You Choose to Live Forever? A Debate. Routledge, 2024.
Fischer, John Martin. Our Stories: Essays on Life, Death, and Free Will. Oxford University Press, 2011.
Fischer, John Martin. Death, Immortality, and Meaning in Life. Oxford University Press, 2019.
Nagel, Thomas. The View from Nowhere. Oxford University Press, 1986.
Williams, Bernard. Problems of the Self. Cambridge University Press, 1973.