Читать книгу Summa Theologica, Part I (Prima Pars) онлайн

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If, however, a thing is called mutable by a power in itself, thus also in some manner every creature is mutable. For every creature has a twofold power, active and passive; and I call that power passive which enables anything to attain its perfection either in being, or in attaining to its end. Now if the mutability of a thing be considered according to its power for being, in that way all creatures are not mutable, but those only in which what is potential in them is consistent with non-being. Hence, in the inferior bodies there is mutability both as regards substantial being, inasmuch as their matter can exist with privation of their substantial form, and also as regards their accidental being, supposing the subject to coexist with privation of accident; as, for example, this subject man can exist with not-whiteness and can therefore be changed from white to not-white. But supposing the accident to be such as to follow on the essential principles of the subject, then the privation of such an accident cannot coexist with the subject. Hence the subject cannot be changed as regards that kind of accident; as, for example, snow cannot be made black. Now in the celestial bodies matter is not consistent with privation of form, because the form perfects the whole potentiality of the matter; therefore these bodies are not mutable as to substantial being, but only as to locality, because the subject is consistent with privation of this or that place. On the other hand incorporeal substances, being subsistent forms which, although with respect to their own existence are as potentiality to act, are not consistent with the privation of this act; forasmuch as existence is consequent upon form, and nothing corrupts except it lose its form. Hence in the form itself there is no power to non-existence; and so these kinds of substances are immutable and invariable as regards their existence. Wherefore Dionysius says (Div. Nom. iv) that "intellectual created substances are pure from generation and from every variation, as also are incorporeal and immaterial substances." Still, there remains in them a twofold mutability: one as regards their potentiality to their end; and in that way there is in them a mutability according to choice from good to evil, as Damascene says (De Fide ii, 3,4); the other as regards place, inasmuch as by their finite power they attain to certain fresh places—which cannot be said of God, who by His infinity fills all places, as was shown above (Q. 8, A. 2).