Equality is in crisis. Our world is filled with soaring inequalities, spanning wealth, race, identity, and nationality. Yet how can we strive for equality if we don't understand it? As much as we have struggled for equality, we have always been profoundly sceptical about it. How much do we want, and for whom? Darrin McMahon's 'Equality' is the definitive intellectual history, tracing equality's global origins and spread from the dawn of humanity through the Enlightenment to today.