Scepticisme ou renoncement au dogme ? Interpréter l'Eucharistie aux XIIIe et XIVe siècles

It is well-known that during the Middle Ages the Eucharist was not only a theological question but also a philosophical one. Recent studies have shown the semantical and ontological problems concerning the status of substances and accidents after the transsubstantiation. Here the paper focuses on the gnoseological problem of the Eucharist. How do we know that the substance has changed after the consecration of the host ? Moreover, how do we manage to know substances in general if sometimes it changes without apparent modifications in the accidental features apprehended by our sense faculties ? The aim of tis paper is to show that a new dilemma appeared at the end of the 13th century between the sceptical consequences of the dogma of transsubstantiation and the necessity to abandon or at least to interpret differently the sacrament. Wyclif chose the second option while most of the theologians and philosophers tried to adapt their theory of knowledge, especially the Franciscans, to which a large part of this paper is devoted. This paper tries to assess the different solutions to this problem of the knowability of substances.