" Critics of disparities often either explicitly or implicitly call for some kind or approximation of equality. But when we speak of “equality” among human beings, what do we mean? We certainly cannot all sing like Pavarotti, think like Einstein or land a commercial airliner safely in the Hudson River like pilot “Sully” Sullenberger. Clearly we cannot all be equally capable of doing concrete things. In terms of specific capabilities in real life, a given man is not even equal to himself at different stages of life—sometimes not even on different days—much less equal to all others who are in varying stages of their own lives. "

― Thomas Sowell , Discrimination and Disparities