 If, on the other hand, the something to which a reason is provided is an actual (i.e., existing) thing, then “reason” stands to explain why that thing as an actual thing comes into existence. Reason, in this sense, is regarded as ratio fiendi or the “reason of becoming”. Recall that for Wolff existence is simply a predicate or determination of possible things. A familiar expression appearing in Wolff’s writings is that existence is “the complement of possibility” (Ont. §174). The basic idea here is that existence, as a predicate, perfects a possible thing by making it actual and a “real individual”. Real individuals differ from nominal beings insofar as the former are “complete and determinate”. To be “complete and determinate”, in Wolff’s sense of the expression, means that every aspect or determination of a thing can be specified and that its determinations are sufficient to individuate it from all other things. Nominal beings, although “complete”, are indeterminate (cf. GL: c. 1, §15). That is to say, although there is a certain set of specifiable determinations that is sufficient to pick out a given possible thing among all possible things, the total set of its determinations is not specifiable. A being, in the most general sense, is comprised of three different types of determinations: essentialia, attributes, and modes. Essential determinations define the essential nature of a being and a being’s attributes follow from, or are determined by, its essentialia. Whereas essentialia and attributes are both necessary properties of a thing, modes are contingent or accidental properties. Thus to say a nominal being is indeterminate is to say that there are modes of it that may or may not be present. In the weakest sense, since existence is a mode, and nominal beings do not exist (as such) but are able to come into existence under certain conditions, all nominal beings are indeterminate.