In an 1843 letter composed on a barge in Holland, a young Karl Marx wrote of a ‘national shame’ that made him want to hide his face. He anticipated his addressee, his friend Arnold Ruge, would remind him that ‘no revolution is made out of shame’. But Marx disagreed. ‘Shame’, he insisted, ‘is already a revolution of a kind’. It is from Marx that Frédéric Gros takes the subtitle of A Philosophy of Shame: A revolutionary emotion. Although we never really discover what kind of revolution Gros has in mind, the book can best be seen as an attempt to revolutionise how we think about shame itself.