Asymmetry Problem

Overview

The Asymmetry Problem is a central issue in population ethics and the ethics of procreation. It concerns an apparent moral asymmetry between:

• a strong reason not to bring into existence a person whose life would be bad or full of suffering, and
• the much weaker (or, on some views, nonexistent) reason to bring into existence a person whose life would be good or worth living.

Many people judge that creating a life of intense suffering is clearly wrong, while failing to create a very happy life seems morally permissible, not a serious wrong. The Asymmetry Problem asks whether this pattern of judgments can be made coherent within a systematic moral theory, and if so, how.

Classical Formulation

In modern analytic philosophy, the Asymmetry Problem is closely associated with Derek Parfit and subsequent debates in population ethics, though related ideas appear earlier in discussions of antinatalism and non-identity.

A simplified formulation uses two contrasting cases:

1. Bad-life creation case:
   Parents knowingly choose to conceive a child who, due to genetic and environmental factors, will have a life dominated by pain, severe disability, or misery, and not worth living overall. Many judge this morally wrong, largely because of what it does to the future person.

2. Good-life omission case:
   Different parents have the opportunity to conceive a child who would almost certainly have a very good life—loving relationships, meaningful work, and substantial happiness. They decide not to conceive. Most people do not see this as comparably wrong, even though a good life fails to occur.

The apparent asymmetry is this:

• The bad-life case seems to involve a strong moral reason against creating the child.
• The good-life case does not seem to involve a strong moral reason in favor of creating the child, even though the created person would benefit greatly.

If morality is supposed to be impartial and focused on the well-being of all affected, this looks puzzling. In both cases, the existence of a possible person is at stake; yet we treat harms as morally decisive while treating missed benefits as, at most, optional considerations.

This tension shows up especially clearly in impersonal consequentialist or total utilitarian frameworks, which typically count it as morally good to add any happy person to the world and morally bad to add an unhappy one. Such theories naturally suggest a kind of symmetry between harms and benefits in population choices, in contrast with common-sense judgments.

Major Responses

Philosophers have proposed several strategies to explain or dissolve the Asymmetry Problem. These differ over whether the asymmetry is:

• a deep truth about morality,
• a mere artifact of common-sense intuition, or
• a sign that we must revise our theories of value and obligation.

1. Person-Affecting Views

Person-affecting theories maintain that moral reasons are fundamentally about making things better or worse for particular individuals.

A common person-affecting response holds:

• We have strong reasons not to create a person for whom life will be bad, because that harms that particular individual.
• We have no strong reason to create a happy person, because failing to create them does not wrong any particular individual; there is no one who is made worse off by their non-existence.

This can vindicate the asymmetry at the cost of accepting that not all good states of affairs matter morally in the same way, and that “benefits” to merely possible people may not generate duties.

Critics argue that this view struggles with other population-ethical puzzles, such as the Non-Identity Problem and the evaluation of policies that predictably affect how many people will ever exist.

2. Impersonal and Utilitarian Approaches

Total utilitarianism and related impersonal views typically deny the strong asymmetry. For them:

• Creating a happy person adds to the total sum of welfare and is therefore morally good.
• Creating a miserable person subtracts from total welfare and is therefore morally bad.

On such views, there is some symmetry: the moral value of an action is a function of its impact on total welfare, regardless of whether it benefits existing or merely possible individuals.

However, defenders often soften the apparent obligation to create happy people by appealing to:

• Demandingness: while it is good to create more happy people, it may not be a strict obligation, given limits on what morality can reasonably require.
• Agent-centered options: individuals may be permitted to prioritize their own projects over maximizing total welfare.

Critics respond that, without further modifications, these theories lead to highly counterintuitive implications, such as strong duties to reproduce whenever one can expect to create lives worth living, and they still do not fully recapture the robust asymmetry of common-sense morality.

3. Benatar’s Anti-Natalist Asymmetry

Philosopher David Benatar gives a distinctive and more radical version of the asymmetry in his defense of anti-natalism. He proposes that:

• The presence of pain is bad.
• The presence of pleasure is good.
• The absence of pain is good, even if there is no one for whom this is a good.
• The absence of pleasure is not bad, unless there is someone for whom this absence is a deprivation.

On this account, failing to create a happy person is not bad (since there is no deprived subject), but creating a suffering person is bad (because someone exists who suffers). Benatar uses this asymmetry to argue that coming into existence is always a harm, and that we have strong reasons not to procreate.

Critics argue that this introduces an unconventional evaluative standard, treating the absence of pain and pleasure in very different ways, and that it is hard to reconcile with more general principles of value.

4. Threshold and Hybrid Views

Some philosophers adopt hybrid or threshold approaches, aiming to preserve some intuitive asymmetry without fully endorsing person-affecting or anti-natalist conclusions. Examples include:

• Threshold asymmetry: It is especially objectionable to create lives below a certain quality-of-life threshold, while the value of creating above-threshold, good lives is real but comparatively weaker and often supererogatory (beyond duty).
• Mixed person-affecting/impersonal views: Reasons not to create miserable lives are person-affecting and stringent; reasons to create very good lives are impersonal and weaker, counting positively but rarely generating strict obligations.

Such views aim to capture common moral intuitions but face challenges of precision (where to set thresholds) and theoretical unity (why person-affecting reasons should systematically outweigh impersonal ones in some domains but not others).

Significance in Population Ethics

The Asymmetry Problem is significant because it exposes a basic tension in how moral theories handle:

• The value of existence: Is coming into existence itself a benefit or harm, or neither, provided the life is above some minimum quality?
• Obligations to possible people: Do we owe anything to those who do not yet exist and might never exist?
• Policy decisions: How should we evaluate climate policy, healthcare prioritization, or reproductive technologies that impact how many and which people will exist?

Proponents of different responses use the Asymmetry Problem as a test case for assessing broader ethical frameworks. Some see a stable asymmetry as a constraint that any plausible moral theory must respect; others interpret common-sense asymmetrical judgments as unreliable, favoring theoretically unified but less intuitive accounts.

Because it touches on questions about procreation, future generations, and the very meaning of moral harm and benefit, the Asymmetry Problem remains a focal topic in contemporary moral and political philosophy, with no consensus resolution. It illustrates how intuitively simple judgments about having children lead to deep and often surprising theoretical challenges.