 Aristotle’s treatment of relations and relatives in the Categories is opaque and incomplete, since (1) he does not have any notion of relation, as he speaks of relatives and conceives of them as those entities to which non-absolute terms of our language refer; (2) he does not discuss the question of the reality of relatives; (3) he does not clarify the connection between the two defi nitions of relatives he proposes in the seventh chapters of the Categories; (4) he does not give any effective criterion for distinguishing relatives from some items belonging to other categories (cf. Ackrill 1963, pp. 98–103). Because of these facts, in the Late Antiquity and in the Middle Ages many authors tried to reformulate the doctrine of relatives. The most successful and interesting attempt was that of the Neoplatonic commentators of the sixth century, such as Olympiodorus, Philoponus, and Simplicius. Unlike Aristotle, they were able to elaborate a notion of relation (schesis) almost equivalent to our modern notion of two-place predicates, as they conceived of relations as abstract forms whose distinctive feature was the property of being present-in and joining two different substances at once. This view was rejected by Latin medieval authors. According to Boethius relation (respectus or habitudo) is an accidental form which is in a substance (its substrate of inherence) and simply entails a reference to another, without inhering in that other. Shortly after the middle of the13th century, Albert the Great explicitly denied that a relation could inhere (in the technical sense of the word) in two substances at once (Liber de praedicamentis, tr. 4, cap. 10). Some years later, the same thesis was held by Simon of Faversham (Quaestiones in librum Praedicamentorum, q. 43). In the 14th century, also Walter Burley shared this approach, since it appeared to him to be the only thing consistent with one of the basic principle of medieval metaphysics: the equivalence and correspondence between accidental forms and their substrates of inherence, so that no accidental form could inhere at the same time and in full in two (or more) substances (cf. Burley, Expositio super librum Sex principiorum, cap. de habitu). On the contrary, Wyclif seems to support a different opinion, similar to that of the Neoplatonists , as he maintained that relation (1) is different from quality and quantity, since it presupposes them, and (2) qua such is a sort of link between two things (cf. Wyclif, De ente praedicamentali, ch. 7. p. 61).