The idea that a just political system must ignore or nullify socially caused initial advantages in competing for positions and other social benefits is as old as political philosophy itself. Plato called for social mobility among his classes so that all could gravitate toward the classes for which their temperaments naturally suited them. The idea that the system must take positive steps to correct for these differences among individuals is likewise as old as the concept of public education, the supposed great equalizer. But the claim that society must correct also for natural differences among individuals – differences in intelligence, talents, beauty, and physical prowess – is far more recent, having been articulated most forcefully by Rawls. The reasoning underlying this further step toward a more radical notion of equal opportunity appeals to the fact that natural differences are equally arbitrary from a moral point of view as a basis for differential rewards as are socially caused differences. A person no more deserves to be born smart than rich. Why then should the former but not the latter be allowed to influence future benefits and rewards? A negative answer, however, creates a tension within a liberal theory of justice between the demand to nullify natural differences, or to use them to the benefit of those least well endowed, and the demand to respect distinct individuals that supposedly grounds such a theory.