This essay deals with the relationship between philosophy and ex- perimental sciences in Carl Stumpf\u2019s epistemology. A student of both Brentano and Lotze, Stumpf also gained scientific training with the physicist Wilhelm Weber in G\uf6ttingen. His double skill set in the fields of philosophy and ex- perimental sciences made his position within the German thought of his time very unusual. Stumpf\u2019s works range from philosophy and phenomenology to experimental investigations into the field of psychology (especially acoustic and musical phenomena, child psychology, animal psychology, psychology of genius). Moreover, he wrote about mathematics, physical acoustics, phonetics and ethnomusicology. Consistent with his personal inclination ...