What Lies Beyond Same‐Sex Marriage? Marriage, Reproductive Freedom and Future Persons in Liberal Public Justification

abstract In this article I consider whether the legalization of sex‐same marriage implies a right to incestuous marriage. I begin by suggesting that the liberal state get out of the ‘marriage’ business by leveling down to a universal civil union status. The question is then whether incestuous unions should be both legal and eligible for this status. I argue that the arguments compatible with public reason for prohibiting them outright, or even for excluding them from the permissible types of legally registered partnerships, are quite weak. The objections to allowing such relations are those from (1) child abuse; (2) unfair burdening of society; and (3) the creation of bad lives. I argue that while rape and other forms of child abuse would be no more legal or tolerated than they are now, the concern about any form of weakening a society's legal and political resources to combat such abuses does indeed register on the justificatory scale, but does not prove that such first‐degree incestuous sexual relations are inherently bad enough to warrant intervention in their own right. I then argue that the concern about unfairly burdening society with unhealthy persons is not as dangerously totalitarian as we might initially fear, but nor is it strong enough to justify an outright prohibition. Finally, I argue that a concern to dissuade persons from creating certain kinds of lives (children with extreme birth defects) is also not as dangerously totalitarian as we might initially fear, and in fact goes further towards explaining why we might have a legitimate interest in intervening. Nonetheless, I argue that the criminalization of such acts only make sense when they are indicators of other offenses, namely negligence or abuse, and it thus seems that the act of consanguineous reproduction is itself insufficient.