While conceptual analysis can be facilitated by computer assistance, the absence of proper models for concepts in text has curtailed the development of such tools. The most common heuristic, which consists in identifying keywords as canonical expression of a concept, poses problems of ambiguity and fails to retrieve most of the relevant textual data. In this paper, we present CoFiH, an algorithm that exploits topics in order to retrieve segments relevant to a given concept. It is then applied to C.S. Peirce's Collected Papers to facilitate the analysis of Peirce's concept of LAW. Compared to the baseline, CoFiH produces better recall and enables a meaningful analysis along several topics.