 Every effort to interpret the concept of equality and to apply the principles of equality mentioned above demands a precise measure of the parameters of equality. We need to know the dimensions within which the striving for equality is morally relevant. What follows is a brief review of the seven most prominent conceptions of distributive equality, each offering a different answer to one question: in the field of distributive justice, what should be equalized, or what should be the parameter or “currency” of equality?