continues, “a substantial union is such a conjunction of two substantial realities that there results from it one substantial something, which is truly and properly one”—“unio enim substantialis, est talis duarum rerum substantialium conjunctio, per quam resultat unum aliquid substantiale quod vere et proprie sit unum,”(297)—and he concludes that “there is something substantial wanting in the human nature of Christ, _viz._ personality, which, of course, is most abundantly supplied in the hypostatic union by the Divine Person”—“reliquum est, ut naturae humanae in Christo aliquid desit substantiale, nempe personalitas, quod per unionem hypostaticam cumulatissime suppleatur a Verbo.”(298) Now, this “aliquid substantiale” cannot be “aliquid naturale” in the sense that it is something _constitutive_ of the human substance or nature; for the human substance or nature of Christ is certainly complete and perfect as a substance or nature. It must be some complement or mode, that is naturally due to it, but supernaturally supplied by the Person of the Divine Word.(299) This brings us to the view that subsistence is a something positive, distinct in some real way, and not merely in our concepts, from the complete individual substance. According to the more common view of catholic philosophers (and theologians) subsistence is some positive perfection really distinct from the complete individual nature. But the supporters of this general view explain it in different ways. We have already referred to the view of certain Thomists who, identifying _subsistence_ with the _actual existence_ of the complete substance or nature, place a real distinction between the existence and the substance or nature. Other Thomists, while defending the latter distinction, point out that actual existence confers no real perfection, but only actualizes the real; they hold, therefore, that subsistence is not existence, but is rather a perfection of the real, essential, or substantial order, as distinct from the existential order—a perfection presupposed by actual existence, and whose proper function is to _unify_ all the substantial constituents and accidental determinations of the individual substance or nature, thus making it a really unitary being—“unum ens per se”—proximately capable of being actualized by the simple existential act: which latter is the ultimate actuality of the real being: _esse est ultimus actus_.(300)