How the great political thinkers have persistently warned against the dangers of economic inequality. Economic inequality is one of the most daunting challenges of our time, with public debate often turning to questions of whether it is an inevitable outcome of economic systems and what, if anything, can be done about it. But why, exactly, should inequality worry us? The Greatest of All Plagues demonstrates that this underlying question has been a central preoccupation of some of the most eminent political thinkers of the Western intellectual tradition. David Lay Williams shares bold new perspectives on the writings and ideas of Plato, Jesus, Thomas Hobbes, Jean-Jacques Rousseau, Adam Smith, John Stuart Mill, and Karl Marx. He shows how they describe economic inequality as a source of political instability and a corrupter of character and soul, and how they view unchecked inequality as a threat to their most cherished values, such as justice, faith, civic harmony, peace, democracy, and freedom. Williams draws invaluable insights into the societal problems generated by what Plato called ‘the greatest of all plagues’, and examines the solutions employed through the centuries. An eye-opening work of intellectual history, The Greatest of All Plagues recovers a forgotten past for some of the most timeless books in the Western canon, revealing how economic inequality has been a paramount problem throughout the history of political thought.