What moral obligations do we owe to living persons that we do not owe to future persons?

To firstly motivate the debate, one of the most obvious ways in which the problem of future generations matters is its implication on what is permissible for us as present generations to do, especially concerning the usage of the earth’s non-renewable resources. This essay will argue that we do owe future persons negative duties of non-harm (a duty not to leave them with a life not worth living), and our policy-making should be shaped accordingly, whereas positive duties of aid and benefit that apply among living persons do not apply to the yet unborn.

Section 1

To see how our duties diverge between present and future people, we must first clarify the obligations we owe to those who already exist. These fall into two broad categories. The first set are negative duties, which bind us to withhold from certain actions. For example, we owe it to those around us to not assault them, because to do so would be to violate their right to non‑interference. Positive duties, by contrast, obligate us to assist when doing so is reasonably within our power: we should, for instance, go into a shallow pond to save a drowning child even if it means ruining our clothes.[i] Both kinds of duty rest on the same intuition: our contemporaries stand to one another not only as potential victims of wrongful harm but also as potential beneficiaries of mutual aid.

This in turn, is further underlay by the fact that our contemporaries stand to us as fellow moral agents; they are capable of grasping reasons, responding to them, and being held answerable for their conduct. A moral agent is, paradigmatically, someone who can reciprocate to the moral sphere of actions; they can make moral judgement, can be held morally responsible and be subject to praise or blame.

Future people, by contrast, cannot yet reciprocate or participate in our moral relationships; at present they are not moral agents. Because many of our obligations hinge on a counterpart’s capacity to reason, respond, and be held responsible, this absence of agency is what fundamentally explains why our duties toward future persons differ from those we owe to our contemporaries.

The remainder of this section will be dedicated to exploring what precisely this difference will be.

A tempting first response is that we owe no duties to future people, because, as suggested by the non‑identity problem, it is impossible for us to harm them. Parfit’s reasoning in formulating this problem has two crucial steps.[ii] The first is what Kavka labels as the “precariousness” of existence: every seemingly minor alteration in timing, technology, or social policy cascades through patterns of conception, so the individuals who will be born under one policy are numerically distinct from those who would appear under another.[iii] Choosing a lax pollution regime today, for instance, not only changes the air quality two centuries later; it also shifts the timing of meetings, and fertilisations etc., thereby give rise to a future generation with an altogether different set of people. The second step invokes a person‑affecting principle[iv]: an action is morally wrong only if it makes some particular person worse off than that same person would otherwise have been, in other words, “what is bad must be bad for someone”. To this end, because each future individual owes her very existence to the policies we adopt, and because non‑existence cannot be a state in which one is better off, no one can claim to be harmed by our decisions. What underlies this conclusion is the idea that non‑existence is not a state in which one can be better or worse off; it lacks a subject of welfare. Consequently, no future person can claim to have been wronged by a choice that is a precondition of her life, however impoverished that life may be. Therefore, since moral wrongness presupposes a victim made worse off, and the non-identity problem shows that our present actions cannot render future individuals worse off, it follows that we owe no obligations to them.

However, this conclusion is deeply counterintuitive. Surely “the great lowering of the quality of life” for future generations gives us moral reason to avoid decisions that cause them to occupy this state. Indeed, if the person-affecting principle implies current people “can do no wrong” in choices that shape future people’s lives, that principle itself becomes suspect.

In this respect, Harman argues that the test misidentifies what it is for a person to be harmed.[v] An act harms someone, she argues, whenever it causally places that person in a state that is intrinsically bad regardless of whether a better alternative life was possible. Because the disvalue of these conditions is non‑relational, we can recognise them without appealing to a counterfactual comparison; they simply lie below a baseline of minimally decent human functioning. Harm is thus assessed non‑comparatively: what matters is that the agent’s choice produces a baseline‑violating state, not how the victim might have fared in some counterfactual scenario. Whenever an action crosses this threshold, it wrongs the person affected through causal production rather than comparative loss.

Once harm is understood in this way, we have independent reasons to argue that the counterfactual state of the victims’ non‑existence drops out of the analysis, because the link between act and bad state is itself sufficient for harm attribution. Therefore, any act that foreseeably brings about such a condition for future persons can be said to harm them.

With this new analysis replacing the person-affecting intuition, this threshold account successfully explains the wrongness in cases of the non-identity problem. Suppose policymakers adopt an energy plan that predictably yields widespread respiratory disease two centuries after. Under the person-affecting intuition, no harm has occurred as those future citizens would not have existed under an alternative regime. The threshold view, however, tracks a straightforward causal line: our present choice creates a state that reaches below the aforementioned baseline, making it intrinsically bad for whoever comes to exist, and this is sufficient for the policy to count as harm to future generations, rendering it morally impermissible.

Section 2

Although we have already seen that our obligations to present and future people diverge, the failure of the non‑identity problem shows that the difference cannot be that we owe the future nothing; our decisions can indeed wrong those who will live later. What follows is not the absence of duty but its restriction in scope. A person who exists now can be the beneficiary of our help or the victim of our harmful actions. By contrast, future persons cannot be helped in the direct way a living person can, because there is no concrete individual to receive a benefit. Therefore, insofar as they are not yet moral agents and cannot engage with us reciprocally, what we owe them is limited to negative duties: we must refrain from decisions that will predictably drive their lives below a threshold of basic decency.

This restriction to negative duties finds systematic support in the asymmetry principle of population ethics.  The asymmetry holds that it is morally wrong to create a person whose life would fall below the threshold of being worth living, yet not wrong to decline to create an additional person whose life would have been happy and high‑quality. Put differently, we are required to prevent misery but not required to manufacture extra happiness. Jan Narveson captures the thought succinctly: morality demands “making people happy, not making happy people.”[vi]

Asymmetry thus clarifies why our forward‑looking obligations stop at prevention rather than provision. A prospective life that would fall below the “worth‑living” threshold gives us a decisive, negative reason to avoid creating it, whereas the prospect of an additional happy life supplies only a weak, permissive reason in its favour. Because merely possible people do not yet exist, they cannot hold present claims to aid, equality, or distributive justice; there is no subject whose interests are set back by our failure to procreate. Once a person does exist, however, she can suffer intrinsically bad states even if, under a different policy, a numerically distinct individual would have occupied her place. Asymmetry therefore reconciles two powerful intuitions: (i) we do no wrong by forgoing the creation of happy lives, because no one is left worse off; yet (ii) we can gravely wrong future persons by bringing them into lives below a minimally acceptable standard, for there will then be an actual sufferer with a legitimate complaint.

To this end, asymmetry explains why we have negative but not positive obligations towards future people; we owe potential future persons protection from harm, but not the positive duties of aid or fairness that we owe to present people.

Notice that this conclusion rejects only Parfit’s person‑affecting intuition while preserving precariousness of existence. Precisely because identity is so easily shifted by tiny changes in present policy, the duties that survive must apply to whoever the future human beings turn out to be, simply in virtue of their personhood, not in virtue of any presently specifiable identity.

Section 3

We have established in previous sections of this essay that, whereas to living persons, we owe them positive obligations, to future people, our obligations are chiefly preventive.

After establishing the kind of duties that we owe to future people, we can flesh out precisely what implications this has on our policy-making. Policymakers should treat large negative impacts on future generations as serious moral constraints on what we may do today. For example, a government deciding on energy policy must weigh not only the benefits to the current population but also the potential long-term detriments. This supports policies such as climate change mitigation, conservation of non-renewable resources and careful management of existential risks (such as nuclear weapons or advanced biotechnologies).

Moreover, since future people cannot presently advocate for their interests, current institutions need to incorporate their representation, for instance, through commissions dedicated to their interests. Such a measure would give institutional voice to our negative duties towards them. Further, fleshing precisely what kinds of duties to owe to future persons also helps us to determine what would count as supererogatory policy-wise. For example, a tax on current society to avert serious future harms is morally required, whereas a tax only to create additional future benefits is not required.

In conclusion, we stand under both positive and negative obligations toward our contemporaries, but only under negative obligations toward those who do not yet exist. Hence, public policy must regard any foreseeable suffering it would impose on future people as a categorical ground for rejection, whereas measures aimed merely at conferring any additional benefits on them remain in the realm of the supererogatory.

[i] Peter Singer, “Famine, Affluence, and Morality,” Philosophy & Public Affairs 1, no. 3 (1972): 229–243.

[ii] Derek Parfit, Reasons and Persons (Oxford: Oxford University Press, 1984), 351–379.

[iii] Gregory S. Kavka, “The Futurity Problem,” in Obligations to Future Generations, ed. R.I. Sikora and Brian Barry (Philadelphia: Temple University Press, 1978), 186–203.

[iv] Parfit, Reasons and Persons, 370.

[v] Elizabeth Harman, “Can We Harm and Benefit in Creating?” Philosophical Perspectives 18, no. 1 (2004): 89–113.

[vi] Heyd, David, “Supererogation”, The Stanford Encyclopedia of Philosophy (Spring 2024 Edition), Edward N. Zalta & Uri Nodelman (eds.), URL = <https://plato.stanford.edu/archives/spr2024/entries/supererogation/>.

Author: Kevin Chen