But what might be so here is not necessarily so. A society could in theory perfectly satisfy careers open to talents while the position in the social hierarchy into which an individual is born entirely determines the prospects for becoming qualified for desirable competitive posts and being selected to fill them. A perhaps more interesting possibility is that a society could perfectly satisfy FEO or some other version of substantive equality of opportunity and also exhibit a very low degree of social mobility or even none at all.  In the illustrative example, this scenario unfolds if the family of origin income decile of every member of society perfectly predicts that person's own family income.