Max Horkheimer, the influential philosopher and sociologist of the Frankfurt School, is most famous for his work on critical theory. But in his book The Critique of Instrumental Reason he focuses on the values of the Enlightenment, the philosophical project that he argues failed to create a rational society. On a busy day at London's Camden Market, Esther Leslie looks at Horkheimer's understanding of 'pseudo-individuality' and his relevance today.With thanks to Verso Books - Radical Thinkers series 7 . To purchase the books in this series at a 25% discount, go here