Non-identity problem

An argument put forth by Derek Parfit against future generations having rights, and therefore against our having to observe those rights towards them.

It goes something like this: if we don't do certain things (recycle, consume less, ZPG, etc.), people 100 years in the future will be worse off. But if we change our actions to help these future people,we will affect the makeup of the future populations. So we just did something to help some people (those existing in the future), but in doing so we have eliminated those people, and replaced them with others (a different future population). Any time you try to do something for these people, they disappear! How can people have rights if they cannot receive the benefits of those rights? (A right is something held by a specific entity.)

It may be that the entity that holds the right is 'the future of humanity', but that seems awfully vague -- particularly since we can't point to any specific entity within this group. And we still face the same dilemma; when we do something to benefit future of humanity x, we immediately destroy it, and create the future of humanity y. For this to work, we have to be working not for a future we expect, but a future we hope for -- a future that doesn't 'exist', even in the vague sense that any future can be said to exist.

It may be that the rights theory of ethics isn't what we should be focusing on in this case. But that just opens more problems; if you are a utilitarian that puts off personal utility to benefit unspecified future generations, wont future generations do exactly the same thing? The future you are trying to benefit, one where people enjoy the fruits of your restraint, will never exist; by endorsing this sort of utilitarianism you guarantee that no one who is moral (in your view) will ever benefit from the moral system. If you follow a duty-based system you might argue that you have a generalized duty to improve the future, with no corresponding right-holders, but without specified right-holders you fall into a new problem. What do you do to make the future 'better' without referring to the people living in it? Don't you have to refer to the people in the future to know what makes a good future? And if you, for example, reduce population growth, aren't you harming all those future people who were never born? We're right back to the beginning.

The term 're-population paradox' is also used to refer to this idea, and for good reason. Most of us understand instantly that this is not true, and that the rights (or something close akin to rights) of future generations are important. Finding a strict description of why they are important, however, is trickier than it looks.

The label 'non-identity problem' comes from Derek Parfit’s book Reasons and Persons (Oxford: Clarendon Press, 1987). The term 're-population paradox' came later, in Thomas Schwartz's paper On the Rights of Future Generations published in Upstream/Downstream: Issues in Environmental Ethics, ed. D. Scherer (Philadelphia: Temple University Press, 1990). While both terms are used, 'non-identity problem' remains the more popular, if non-descriptive, of the two.

In context, it concerns the question of whether people in the future (i.e. not alive at the present time) can have rights which we can or should respect. For example, a right to clean air. If we do decide to accord such rights, then it follows that we should take all necessary steps to ensure that they are respected. Hence, rights-based ethics.

The supposed paradox is that the existence of such people directly depends on our actions at present. We cannot imagine a specific person alive 100 years from now who, under one particular policy, does not have clean air, then alter the current policy such that he does, since almost certainly as the result of the alteration in policy the world would no longer contain this specific person. In the fanciful jargon of the paradox-maker, the world has been "re-populated" by the change of policy.

Now, supposedly, rights can only be granted to specific people (or other entities). That is, it is logically impossible to give X a right to clean air (say) if we don't know who X is. However, since it is clearly impossible to specify individuals 100 years in the future, we cannot consider them as having any rights at all.

Note that this is logically distinct from granting future rights per se: no objection (except possibly sexism) is raised to granting the eldest son of Y the right to enjoy his inheritance when of age, even though such a person may or may not exist: because if such a person does exist he is already unambiguously specified (up to paternity suits...).

This example gives us a clue as to why the supposed paradox is not. If we are fair-minded, for the great majority of rights that we might wish to bestow, we wish to bestow equally on all persons alive at a given time and place. For example, one might wish to bestow on the people of Iraq the right to a free and fair trial, or freedom of speech. And this wish would obtain whether Iraq's population consisted of the people currently alive there, or another set of 23 million people with entirely different names, shoe sizes and tastes in music. We do not have to specify entities very much to give them rights. (We say "people of Iraq" simply because Iraq is a convenient geographical division of the world.)

Since we can, and do, conceive of giving rights to groups of people who are only very weakly specified, we can quite legitimately conceive of giving rights to people living 100 years in the future. Always assuming that there are people alive then. Like "people of Iraq", "people living 100 years in the future" are already specified enough for us to think of their rights.

The fallacy of the supposed paradox can be even more easily seen by considering the question of whether we want people in the U.S.A. 30 years from now to have the right of trial by jury. Decisions being made now (for example, which Supreme Court justices to appoint, which President to elect) may well affect this right in the future. Such decisions will equally have some effect on the future make-up of the population. But we don't conclude that it is therefore impossible to consider people having this right in the future.

One of the great abilities of human intelligence is generalization: the ability to conceive of classes of entities, and not just individuals. We have used this ability to imagine giving rights to people in general, who would receive such rights merely by virtue of being human. We might discuss giving rights to individuals by virtue of their being specific people and not anyone else, for example whether John Kettley, or Annabelle Giles, should have the right to clean air. But such a discussion is by its very nature inequitable, if not iniquitous. For any right worth the giving, we would give it equally to one set of people or to their "re-populated" replacements: to the people living 100 years from now, whoever they may be.

Of course, it may be that in a few thousand years humans have evolved to benefit from particulates in the air; or are living mainly as disembodied brains. But that's a simple problem of our inevitable ignorance of the far future, and no paradox.