By Walter Glannon.

At some point in the future, the human species may cease to exist. Extinction could result from an asteroid striking Earth, a pathogen overwhelming the immune system, the effects of climate change, or other events.  We currently have no control over the first cause, some control over the second, and more control over the third.  Technology that could deflect asteroids is being tested, but it is not clear whether it would be effective. Vaccines can control many viruses, though some can evade the immune response they are designed to induce.  Humans may not always win the competition with pathogens.  Limits on fossil fuel and methane emissions, deforestation, and other processes can reduce the concentration of greenhouse gasses and their effects on climate. But the necessary steps to reduce them have not been taken.

Suppose that we become extinct from any of these existential threats.  Would this be bad?  The immediate and short-term effects would harm existing people because it would cause them to suffer and shorten their lives.  Assuming that life for them was good on balance, extinction would be bad because it would deprive them of continued life.   A gradual process of extinction would be worse than a rapid one because more people would suffer longer.  If earlier extinction reduced the suffering people would experience, then it would be better if it occurred sooner rather than later.  Events occurring in the process of going extinct are different from the state of extinction itself.  Presumably, it would be bad if no human existed.  But bad for whom?  For possible future people who might have existed but will not actually exist?   How could it be bad for them?  We can be harmed by events we cannot experience but that adversely affect us and our biological and biographical lives in other ways.  Yet our being harmed by them assumes that we have interests in these events when we exist.  If benefit, harm and other measures of human well-being pertain to actual but not possible people, then it seems that possible people who will not exist cannot be affected by a state of extinction.  For possible people, it would not matter morally whether humans became extinct sooner or later because extinction would not affect them.

The claim that a person can benefit from or be harmed by an action, event or series of events implies that they are better or worse off than they were before it occurred.  This presupposes two distinct states of affairs in which the same person exists.  Possible people do not exist.  They are not persisting identifiable individuals with an interest in being brought into existence.  If they do not have interests, then they cannot benefit from or be harmed by existence as such.  They have no claim to actually exist, and thus there is no obligation for actual people to cause them to exist.  Bringing someone into existence is nether good nor bad because this does not make ‘them’ better or worse off than ‘they’ were before.  Whether someone is positively or negatively affected depends on the life they have after coming into existence.

For many, human existence seems intrinsically valuable.  But what gives it this value?  On what grounds could one argue that existence has intrinsic value, and that nonexistence has intrinsic disvalue?  Some might argue that bringing people into existence would improve the world.  This would be necessary for human to make moral progress.  Even if it did, it would give human existence instrumental rather than intrinsic value.  This value would depend on their level of well-being and the quality of their lives, not on existence itself.

Extinction might be bad in an impersonal sense if it meant that there would not be any more good lives.  But it would not be bad in a personal sense because no one would actually  experience pain and suffering.  Although the incidence of global hunger per capita has declined over the last century, hunger still affects 9-10 percent of the human population.  Extreme poverty has also declined, but approximately 100 million additional people are living in poverty as a result of the SARS-Cov-2 pandemic.  These numbers will rise as the adverse effects of political instability and climate change on the global population accelerate.   As the numbers increase, so will the scale of suffering from these social and natural factors.

Reflecting on the hypothetical situation in which you could deflect an asteroid about to strike Earth, Roger Crisp notes that “these numbers, and the scale of suffering to be put into the balance alongside the good elements in individuals’ lives, are difficult to fathom and so large that it’s not obvious that you should deflect the asteroid.  In fact, there seem to be some reasons to think you shouldn’t.” Many future lives in this world would not be good.  The moral obligation to prevent suffering may provide a pro tanto reason for preventing the existence of people who would have these lives.  Still,  Crisp claims that the value of the continued existence of humans is an open question. He does not claim that “extinction would be good; only that, since it might be, we should devote a lot more attention to thinking about the value of extinction than we have to date.”

We cannot predict the sort of lives future people would have because we do not know the sort of world they would inhabit.  But the circumstances described above make it difficult to be optimistic. Regardless of the hypothetical value or disvalue of these lives, possible people are not deprived of anything if they do not come into existence.  We have an obligation to collectively act to prevent or reduce the suffering that present and future humans will actually experience. This depends on controlling natural habitats, deforestation, carbon emissions and other processes.  Future actual people have the same rights and interests in avoiding suffering as present actual people.  The extent of suffering may provide a pro tanto reason to prevent them from existing.  Even if there is no such reason, merely possible people do not have these rights and interests because they do not and will not exist.  If we become extinct, then the world will go on without us and will be good or bad for no one.

Author: Walter Glannon

Affiliation: Department of Philosophy, University of Calgary

Competing Interests: None.

This article is part of a broader philosophical debate on the moral significance of human extinction.