64. ERRONEOUS VIEWS ON THE NATURE OF SUBSTANCE.—If we fail to remember that the notion of substance, as “a being existing in itself and supporting the accidents which affect it,” is a most abstract and generic notion; if we transfer it in this abstract condition to the real order; if we imagine that the concrete individual substances which actually exist in the real order merely verify this widest notion and are devoid of all further content; that they possess in themselves no further richness of reality; if we forget that actual substances, in all the variety of their natures, as material, or living, or sentient, or rational and spiritual, are indeed full, vibrant, palpitating with manifold and diversified reality; if we rob them of all this perfection or locate it in their accidents as considered apart from themselves,—we are likely to form very erroneous notions both of substances and of accidents, and of their real relations to one another. It will help us to form accurate concepts of them, concepts really warranted by experience, if we examine briefly some of the more remarkable misconceptions of substance that have at one time or other gained currency. (_a_) Substance is not a concrete core on which concrete accidents are superimposed, or a sort of kernel of which they form the rind. Such a way of conceiving them is as misleading as it is crude and material. No doubt the language which, for want of better, we have to employ in regard to substance and accidents, suggests fancies of that kind: we speak of substance “supporting,” “sustaining” accidents, and of these as “supported by,” and “inhering in” the former. But this does not really signify any juxtaposition or superposition of concrete entities. The substance is a subject determinable by its various accidents; these are actualizations of its potentiality; its relation to them is the relation of the potential to the actual, of a “material” or “determinable” subject to “formal” or “determining” principles. But the appearance or disappearance of accidents never takes place in the same concrete subject: by their variations the concrete subject is changed: at any instant the substance affected by its accidents is one individual concrete being (27), and the inevitable result of any modification in them is that this individual, concrete being is changed, is no longer the same. No doubt, it preserves its substantial identity throughout accidental change, but not its concrete identity,—that is to say, not wholly. This is the characteristic of every finite being, subject to change and existing in time: it has the actuality of its being, not _tota simul_, but only gradually, successively (10). From this, too, we see that although substance is a more perfect mode of being than accident—because the former exists in itself while the latter has its actuality only in something else,—nevertheless, created, finite substance is a mode of being which is itself imperfect, and perfectible by