  Following Boethius, medieval philosophers often take Aristotle’s use of the plural to indicate that the category of relations must be at least conceived of as containing pairs of correlatives or converse relational accidents (see, e.g., Abelard, Logica ‘ingredientibus’, 80–95; and Albert the Great, Liber de praedicamentis, 22). As we shall see, this point becomes important for their understanding of those relational situations that do not conform to the paradigm analysis of the Categories.