This chapter explains how the semiotic revolution provided a new framework for the analysis of knowledge by considering not only the nature of the objects studied, but also the way the objects are presented to us and how we can access them on our own. It presents a brief historical overview of the development of semiotics since the end of the nineteenth century by reviewing the theories of Peirce, Saussure and Frege and argues for the need to develop a particular semiotic model to analyze the specificities of mathematical knowledge.