 Okin argues that the gender system violates both the liberty and equality of opportunity principles because by effectively assigning roles to citizens according to sex it circumvents citizens’ “free choice of occupation” (Okin 1989: 103). On Okin’s view, this means that in a just society “gender could no longer form a legitimate part of the social structure, whether inside or outside the family” (1989: 103). None of the institutions of the basic structure, including the family, could assign roles according to sex. It is common to argue that the state, educational institutions and workplaces should not assign roles according to sex. But Okin argues that this applies to the family as well. Gender blindness must play the same role in the family that it plays in these institutions. In Okin’s words, there must be “congruence” between the principles that govern these institutions and those that govern family life (1989: 21). That is, families must be just.