In his book, Death and the Afterlife, Samuel Scheffler offer two imaginative thought experiments in an attempt to understand our attitudes toward death and meaning.
In the first, the doomsday scenario, we are asked to imagine that we will live out our normal lifespan, but that thirty days after our deaths an asteroid will destroy the earth and all life on it. Needless to say, most of us would find this a depressing prospect, independent of the fact that we would not die prematurely. Scheffler argues that this shows that the lives of others who live on after we die, what he calls the “collective afterlife,” matter more to us than we ordinarily think and that our individual survival matters less to us than we normally suppose.
In the second, the infertility scenario, we again live out our normal lives but must do so with the knowledge that the species is infertile. With the last human death, humanity dies out. Scheffler argues that this knowledge would demoralize us, undermining our attempt to live happy lives. Again we see that the collective afterlife is more important to us than we usually realize.
Scheffler then contrasts the relative calm we feel about the fact that all those now living will one day be dead, with the horror we experience thinking about either of the above scenarios. This suggests that the fact that we and those we love won’t exist in the future bothers us less, than that some unknown people won’t exist in the future. As Scheffler says:
the coming into existence of people we do not know and love matters more to us than our own survival and the survival of the people we do know and love. . . . This is a remarkable fact which should get more attention than it does in thinking about the nature and limits of our personal egoism.
MARK JOHNSTON REPLIES
But is it true that we really care more about the existence of potential people than the survival of our loved ones? This idea was challenged in a piece in the Boston Review by Mark Johnston entitled, “Is Life a Ponzi Scheme? Johnston asks us to imagine that the population of our tribe is half of humanity, and our tribe is also infertile. Would we really prefer the death of our tribe if we knew that the remaining half of humanity will repopulate the planet to its previous levels in a few generations, and then all of them will die a few generations later? Johnston thinks most of us would answer no to this question, and that his thought experiment belies Scheffler’s claim that we care more about unknown future persons than our present loved ones.
Johnston also argues that it is not just any future for humanity that matters to us, but valuable ones. Thus a future in which gangs fight for cosmic space or we are food for aliens is not better than one in which we perished altogether. Johnston prefers we perish rather than suffer such fates. This leads him to consider whether our lives have meaning: a) if humanity has a future or; b) only if humanity has a valuable future. The problem with either of these is that if value depends on the future, then value will eventually be undermined—since the universe will ultimately end.
To avoid such a depressing conclusion Johnston advises us to value our lives now rather than holding them hostage to some future. And we should not be demoralized by the thought of our own or humanity’s death: “The kind of value that properly calls forth joy is not something that waits to be validated by the collective life to come. As a consequence, we already live in a rich ecology of value that surrounds us here and now, no matter what happens in the future.”
I challenged Johnston’s views in my book: The Meaning of Life: Religious, Philosophical, Transhumanist, and Scientific Perspectives. There I argue that what I call complete meaning is not possible without both individual and collective immortality. That is not to say that mortal beings can’t live meaningful lives, just that such lives would be completely meaningful only if they possessed both infinite quantity and quantity—only if they didn’t end. In my view, this is possible because future technologies may make death optional and grant us immortality if we so choose.
This argument for immortality provided by future technologies is buttressed by Scheffler’s insight that we care about future people. We care about the future because without it life is (nearly) pointless. Johnston is right that without a future there is little meaning to life. But if there is a valuable and meaningful future—made possible by science and technology—then acting to bring about the future gives life meaning. As for the eventual death of the universe, this is uncertain given considerations of the multiverse and the possibility of powerful, advanced intelligence determining the fate of the universe.
Without the prospect of a good and lasting future for our descendants, there is little or no meaning to our present lives. And that is what Scheffler’s thought experiments so beautifully and artfully illuminate.