  It should be noted that the issue, how to measure people's condition for purposes of a theory of equality, connects to a broader issue, how to measure people's condition for purposes of a theory of fair distribution. Equality is just one of the possible views that might be taken as to what fair treatment requires. (For example, the sufficientarian and prioritarian principles discussed in the text below both admit of resourcist and welfarist and “capabilitist” variants.) Any theory of distributive justice that says that sometimes better off persons should improve the situation of worse off persons requires an account of the basis of interpersonal comparisons that enables us to determine who is better off and who is worse off.