Professor of Philosophy, Freie Universität Berlin; 2000-2006 Member of the ‘Wissenschaftsrat‘ (German Scientific Council); 2005-2008 permanent fellow Wissenschaftskolleg zu Berlin; 2007-2014 Member of the Panel of the European Research Council, Brüssel; 2008-2013 Chair of the ‚Doctoral School‘: ‚Notational Iconicity‘; 2009 – 2016 Member of the Senat of the DFG. Visiting professor: Technical University Vienna, Austria; Max Reinhard Seminar Vienna Austria; University of Graz, Austria; Luzern University, Swiss, Zürich University Swiss; Tokyo University, Japan. Doctor honoris causa by Linköping University/Sweden.

Research fields: Philosophy of language, images and writing; Mediaphilosophy; Diagrammatology; Epistemology and Theory of Mind; Philosophy of Culture; Ethics and Episteme of Testimony; Theorizing Digitality.

Last (English) publications.: Medium, Messenger, Transmission. An Approach to Media Philosophy, Amsterdam: UP 2015 (germ. 2008, jap. 2014); ed. with Chr. Ljungberg: Thinking with diagrams, Boston/Berlin: de Gruyter 2016; ed. with Sigrid Weigel: Testimony/Bearing Witness. Epistemology, Ethics, History and Culture, London: Rowman & Littlefield 2017.