A philosopher looks at string dualities

Many of the advances in string theory have been generated by the discovery of new duality symmetries connecting what were once thought to be distinct theories. Indeed, duality has played an enormously important role in the creation and development of numerous theories in physics and numerous fields of mathematics. Dualities often lie at those fruitful intersections at which mathematics and physics are especially strongly intertwined. In this paper I describe several of these dualities and unpack some of their philosophical implications, focusing primarily on string theoretic dualities.