Whoever might be looking for proof that working on classical philosophical works does not inevitably entail dispensing with a horizon of thought governed by renewal and expansion should turn to the works of Michael Theunissen. Born in Berlin in 1932, Theunissen should be seen as one of the most influential modern-day philosophers who has uncovered unexpected and innovative theoretical potential with his reconstruction of philosophical history. Having studied philosophy and German in both Bonn and Freiburg, he chose Kierkegaard as the subject of his Ph.D., which he obtained under Max Müller’s mentorship in 1955. In 1965 he published his post-doctoral thesis on social analysis: Der Andere. Studien zur Sozialontologie der Gegenwart.1 In the times that followed Theunissen not only made a lasting mark with his manifold publications that met with a wide appreciative audience-it was also as an academic teacher that he made a lasting impression on generations of students, initially in Basel and later on in Heidelberg and Berlin.