In 1973, an employee of the Deutsche Bank in Heidelberg identified the influential sociologist of literature and Marxist György Lukács (1885-1971) as the owner of a mass of material that had been deposited there in 1917. Among the sixteen hundred letters and text fragments of the collection, known as the "Heidelberg Suitcase" among researchers, was the notebook that has been partially reproduced in this publication. The content of the notebook is in two parts: In the front are notes Lukács took in German during lectures by Georg Simmel on "Logic and Problems of Contemporary Philosophy," held at the Berlin University in 1906. A few years later, Lukács used the notebook again and, starting from its end, wrote in Hungarian a draft with the title "Sociology of Art."With an introduction by Lívia Páldi, Chief Curator at the Mucsarnok/Kunsthalle Budapest and Agent for dOCUMENTA (13).