sentences:  He graduated in 1987 in Germanic Studies, Philosophy and History at the Albert-Ludwigs-Universität Freiburg/Germany.He followed Friedrich Kittler, with whom he had worked already in Freiburg, to the department of Germanic studies at the Ruhr University Bochum, where he received his doctorate in 1991.In 2001 he earned a Habilitation at the Humboldt University Berlin.