Professor of Philosophy at Humboldt-Universität Berlin and the president of the German Society for Analytical Philosophy (GAP). His main areas of research are the philosophy of action, epistemology, philosophy of language, metaphysics, and the philosophy of free will. His book publications include Handeln und Verursachen (2000), Fifty Years of Quine’s ‘Two Dogmas’ (2003), Willensfreiheit (2007), Quine (2011), Vagueness and Ontology (2013), Vagueness and Law (2016), Aristotle’s Anthropology (2019), and Wenn ich mich nicht irre (2019).