Abstract
The paper presents a theoretical framework for a hermeneutic approach based on the interpretative line proposed by Bagni (2009). Our purpose is to show how this approach may serve as the basis of work with historical sources in teachers education. Its advantage is that it enables to present also teachers positions incommensurate with current mathematical discourse, thus relaxing the need for coherence imposed by an epistemological approach to learning. As an example of the approach, we look at the history of probability.