 The concept of being, all the medievals agreed, is common. What was debated was the nature of this commonness. According to James of Viterbo, all commonness is founded on some agreement, and this agreement can be either merely nominal or grounded in reality. Agreement is nominal when the same name is predicated of wholly different things, without there being any objective basis for the application of the common name; such is the case of equivocal names. Agreement is real in the following two cases: (1) if it is based on some essential resemblance between the many things to which a particular concept applies, in which case the concept applies to these many things by virtue of the self-same ratio and is said of them univocally; or (2) if that concept is truly common to the many things of which it is said, although it is not said of them in relation to the same nature (ratio), but rather it is said in a prior sense of one and in a posterior sense of others, insofar as they are related in a certain way to the first. A concept that is predicated of things in this way is said to be analogous, and the agreement displayed by the things to which it applies is said to be an agreement of attribution (convenientia attributionis). James believes that it is according to this sense of analogy that being is said of God and creatures, and of substance and accident (Quaestiones de divinis praedicamentis I, q. 1, p. 25, 674–80). For being is said in a prior sense of God and in a posterior sense of creatures by virtue of a certain relation between the two; likewise, being is said first of substance and secondarily of accidents, on account of the relation of posteriority accidents have to substance. The reason why being is said in a prior sense of God and in a secondary sense of creatures and, hence, the reason why the ‘ratio’ or nature of being is different in the two cases is that being, in God, is “the very thing which God is” (Quaestiones de divinis praedicamentis, q. 1, p. 16, 412), whereas created being is only being through something added to it. From this first difference follows a second, namely, that created being is being by virtue of being related to an agent, whereas uncreated being has no relation. These two differences can be summarized by saying that divine being is being through itself (per se), whereas created being is being through another (per aliud) (Quaestiones de divinis praedicamentis, q. 1, p. 16, 425–6). In sum, being is said of God and creature, but according to a different ratio: it is said of God according to the proper and perfect nature of being, but of creatures in a derivative or secondary way.