The aim of this introduction is to offer a brief outline of Bohr’s complementarity as an interpretation of quantum mechanics and of the phenomena in question in it, quantum phenomena. This outline may be seen as primarily philosophical insofar as it aims to delineate the philosophical content of Bohr’s key concepts. I shall, however, also discuss their physical content, both in its own right and in order to elucidate their philosophical content, or rather to use their physical and philosophical content to elucidate each other, and thus to understand better the reciprocity between physics and philosophy in the architecture of these concepts
