Definition
The Non-Identity Problem is a philosophical paradox arising from the observation that our actions and policies often determine which individuals will exist in the future. Because even small changes in timing or conditions change the identity of future people, we cannot say that a policy “benefited” a specific future person if they would not have existed without that policy.
Why It Matters
The Non-Identity Problem is a “moral landmine” for long-term planning. It challenges our intuitive reasons for protecting the environment: if we can’t say we are “helping” a specific future child, does our duty to them vanish? This paradox forces us to move beyond “person-affecting” ethics toward a more robust, “impersonal” morality. It is the essential philosophical groundwork for Longtermism, ensuring that we value the quality of future life even when the specific identities of those people are a direct consequence of our current actions.
Core Concepts
- Identity Fragility: The identity of a person is dependent on the specific sperm and egg that meet. Any event that slightly alters the timing of a parent’s day (e.g., taking the bus vs. driving) will likely result in a different child being born.
- The Identity Cascade: A small change today (like a carbon tax) triggers an “identity cascade” where, within a few decades, everyone born is a different person than they would have been otherwise.
- The Paradox of Benefit: If Alice is born into a world with climate change, and Bob is born instead if we fix climate change, we haven’t “helped” Alice by fixing it—we’ve prevented her from ever existing.
- Moral Irrelevance of Identity: MacAskill and Parfit argue that the fact that identity changes doesn’t reduce our moral reasons to make the future better. We have reason to bring into existence the population with the higher wellbeing, regardless of who is in it.