Abstract
Brousseau’s Theory of Didactical Situations (TDS) offers a general model for the analysis of didactical systems: in short, the students act upon a milieu which, in turns, informs or sanctions them. Our main idea is to combine TDS with tools from Philosophy, around the notion of horizon, in order to develop further the hermeneutical and phenomenological dimensions of the learner’s interaction with the milieu. The fertility of combining theoretical constructs from Philosophy and Didactics, in the spirit of networking theories as a research practice in Mathematics Education research, has been evidenced through previous research in which we draw connections between the didactic contract and the notion of horizon of expectation as developed by Jauss and the Constance School. Our analyses lead to a typology of horizons and its pioneering application in the context of the teaching and learning of mathematical structuralism at university level.