Alyngton’s theory of ad aliquid is worthy of note, as he possibly was the only late medieval author who followed and developed Wyclif ’s ideas on that topic.  He conceived of relation (relatio) as an accidental form which is present in both the relatives at once – even though in different ways, since it names only one of them. Consequently his relation can be considered as a sort of ontological counterpart of our modern functions with two variables, or two-place predicates (In Cat., cap. de relativis, pp. 295–96).  According to Alyngton, whose account partially differs from that of Wyclif, in the act of relating one substance to another four distinct constitutive elements can be singled out: (1) the relation itself – for instance, the form of paternity; (2) the subject of the relation, that is, the substance that denominatively receives the name of the relation – for instance, the (substance that is the) father; (3) the object of the relation, that is, the substance which the subject of the relation is connected with – for instance, the (substance that is the) son; and (4) the foundation (fundamentum) of the relation, that is, the absolute entity in virtue of which the relation inheres in the subject and in the object (ibidem, p. 299). The foundation is the main component, since it joins the relation to the underlying substances, lets the relation link the substrate to the object, and transmits some of its properties to the relation (ibidem, p.  291). Like Wyclif, Alyngton affirms that only qualities and quantities can be the foundation of a relation (ibidem). Some consequences about the nature and status of relations and relatives derive from these premises: (1) relation is a categorial item whose reality is feebler than that of any other accidental form, as it depends upon the simultaneous existence of three different items: the subject, the object, and the foundation (ibidem, p. 295). (2) A relation can start inhering in a substance without any change in the latter, but simply because of a change in another substance. For example: given two things, one white and the other black, if the black thing becomes white, then, because of this change, a new accident, that is, a relation of similarity, will inhere also in the fi rst thing, apart from any other change in it. (3) All the real relatives (relativa secundum esse) are simultaneous by nature, since the real cause of being a relative is relation, which at the same time inheres in two substances, thereby making both ones relatives (ibidem, p. 301). On this basis Alyngton can divide relations into transcendental and categorial relations (ibidem, pp. 290–91), and, what is more, among the latter he can contrast real relatives (relativa secundum esse) with relatives of reason (relativa rationis) without utilizing references to our mental activities nor to semantic principles. In fact, on the one hand, Alyngton describes real relatives as those aggregates (1) made up of a primary substance, (2) an absolute accidental form (quantity or quality), and (3) a relation which correlates the substance at issue to another substance existing in actu. On the other hand, he defi ne relatives of reason as those aggregates characterized by the occurrence of at least one of these negative conditions: (1) either the relation’s subject of inherence or its object is not a substance; (2) the object is not an actual entity; (3) the foundation of the relation is not an absolute accident (ibidem, p. 293). The strategy which supports this choice is evident: Alyngton wanted to substitute references to mental activity with references to the external world, thus using only objective criteria, based on the framework of reality itself in order to classifying things.