Olaf L. Müller studied philosophy, mathematics, economics, and computer science at Göttingen University (Germany) and UCLA. In his PhD thesis he repudiated Quine's meaning skepticism within Quine's own framework ("Synonymie und Analytizität", Paderborn, 1998). He has formulated and defended a new version of Putnam's argument against the brain-in-a-vat scenario. Since 2003, he holds a chair of philosophy at Humboldt University, Berlin; his main interest concerns Goethe's protest against Newton's Opticks, but he works about many other subjects such as pacifism, metaphysics, religion, freedom, dualism.