The idea of socialism was theoretically justified more than 150 years ago as a counteraction to capitalist society, but today it seems to have lost much of its appeal. What explains the rapid decline of this powerful idea, and what can we do to update it for the 21st century? Axel Honneth examines the answers to these questions in his political and philosophical study, which received the Bruno Kreisky Foundation award in the “Political Book” category in 2015.