The Upward Gap: Human Enhancement and the Hidden Assumption of the Social Contract

Abstract The ethics of human enhancement has mostly asked whether enhancement is permissible and whether it benefits the person enhanced. This article asks what enhancement does to the conditions under which justice holds among people. It argues that the social contract tradition, from Hobbes and Hume to Rawls, rests on an assumption of approximate equality: no one is so strong that others cannot resist, and no one so self-sufficient as to need no one. The article reconstructs this assumption, separates its two foundations, the capacity to resist and mutual need, and proposes four indicators and a threshold rule by which its erosion can be assessed. Critics of the tradition have shown how it fails people who fall below the range it assumes. Enhancement creates the reverse case, an upward gap, in which those with the power to decide 1 are the very people who could leave the circumstances of justice. Distinguishing the justification of equality from its stability, the article argues that enhancement leaves the first intact and threatens the second. It identifies the need for acceptance by an independent witness as a ground of stability that no enhancement removes, answers an objection drawn from Hegel’s account of lordship and bondage, and sketches the terms of a founded equality, with criteria by which any pact for coexistence can be judged. Keywords: human enhancement; social contract; approximate equality; circumstances of justice; recognition; stability