  Topos theory has been suggested by D\"oring and Isham as an alternative
mathematical structure with which to formulate physical theories. In
particular, the topos approach suggests a radical new way of thinking about
what a theory of physics is and what its conceptual framework looks like. The
motivation of using topos theory to express quantum theory lies in the desire
to overcome certain interpretational problems inherent in the standard
formulation of the theory. In particular, the topos reformulation of quantum
theory overcomes the instrumentalist/Copenhagen interpretation thereby
rendering the theory more realist. In the process one ends up with a
multivalued/intuitionistic logic rather than a Boolean logic. In this article
we shall review some of these developments.
