 A related, but distinct, line of thought invokes the alleged psychological effects of two-parent families to argue that marriage benefits society by promoting good citizenship and state stability (Galston 1991, 283–288). This depends on the empirical case (as we have seen, a contested one) that children of single parents face psychological and economic hurdles which threaten their capacity to acquire the virtues of citizenship. Moreover, if economic dependence produces power inequality within marriage, then Mill’s ‘school of injustice’ objection applies—an institution teaching injustice is likely to undermine the virtues of citizenship (Okin 1994, Young 1995).