 According to Alyngton, who depends on Avicenna and Wyclif on this topic, the formal universals are common natures in virtue of which the individuals that share them are exactly what they are, just as humanity is the form by which every man formally is a man. Unlike Wyclif, however, he does not think that universals exist in actu in the external world (see Alyngton, Litteralis sententia super Praedicamenta Aristotelis., ch. de substantia, in A.D. Conti, "Linguaggio e realtà nel commento alle Categorie di Robert Alyngton," Appendix (provisional edition of part of Alyngton's commentary on the Categories), Documenti e studi sulla tradizione filosofica medievale, 4 (1993): 179-306, at p. 279). As natures, they are prior and indifferent to any division into universals and individuals. Although universality is not a constitutive mark of the nature itself, it is its unique, inseparable property. Also for Alyngton, universals are really identical-to and formally distinct-from their individuals. In fact, universals are formal causes in relation to their own individuals, while individuals are material causes in relation to their universals (see Litteralis sententia super Praedicamenta Aristotelis., ch. de substantia, pp. 275-76). On this basis, Alyngton stated that (1) a universal in the category of substance can directly receive only the predications of substantial forms more common than it. So, for instance, only corporeity and animality can be directly predicated of humanity. And (2) the accidental forms inhering in individual substances can be predicated of the universal substantial form that those individuals instantiate only indirectly (or essentialiter according to his terminology) through and in virtue of the individuals themselves of that substantial form (see Litteralis sententia super Praedicamenta Aristotelis., ch. de substantia, pp. 288-89). For instance, the general form of whiteness can be indirectly predicated of the general form of humanity in virtue of the individual forms of whiteness which inhere in individual men.