 1. (Quantity) According to the standard realist interpretation of the Aristotelian doctrine of the categories, followed also by Alyngton among the nine genera of accidents, quantity is the most important one, as it is the basis of all further accidents, since quantity orders material substances for receiving quality and the other accidental forms (In Cat., cap. de quantitate, fol. 106r). On the contrary, Ockham had claimed that it was superfluous to posit quantitative forms really distinct from substance and quality, since quantity presupposes what it is intended to explain, that is, the extension of material substances and their having parts outside parts. As an accident, quantity needs substance as its substrate of inherence (cf. Ockham, Expositio in librum Praedicamentorum Aristotelis, cap. 10.4, in Opera philosophica, vol. 2, pp. 205–24). Like Burley and Wyclif, Alyngton denies that material substance can be actually extended without the presence of the general form of quantity in it, thereby affirming its necessity. Hence, he tries to confute Ockham’s argumentation. He thinks that the existence of quantity always implies that of substance, but he also believes that the actual existence of parts in a substance necessarily implies the presence of a general form of quantity in it, really distinct from the substance (say Socrates) in which it inheres, and formally distinct from the fact, grounded on the substance at issue, that this same substance is a quantified thing. For Alyngton, what characterizes quantity and differentiates it from the other accidental forms, and in particular from quality, are the following features: (1) being the appropriate measure of anything, and (2) being an absolute entity which makes it possible that material substances actually have parts outside parts (In Cat., cap. de quantitate, fols. 106v, 107r, 114v).