Thus, substance is conceived as the unique but hidden and [pg 229] unknowable basis of all the phenomena which constitute the totality of human experience.
What is to be said of such a conception? There is just this much truth in it: that substance is relatively stable or permanent, i.e. in comparison with accidents; the latter cannot survive the destruction or disappearance of the substance in which they inhere, while a substance can persist through incessant change of its accidents. But accidents are not absolutely ephemeral, nor is substance absolutely permanent: were an accident to exist for ever it would not cease to be an accident, nor would a substance be any less a substance were it created and then instantaneously annihilated. But in the latter case the human mind could not apprehend the substance; for since all human cognitive experience takes place in time, which involves duration, the mind can apprehend a substance only on condition that the latter has some permanence, some appreciable duration in existence. This fact, too, explains in some measure the error of conceiving permanence as essential to a substance. But the error has another source also: Under the influence of subjective idealism philosophers have come to regard the individual's consciousness of his own self, the consciousness of the Ego, as the sole and unique source of our concept of substance. The passage we have just quoted from Spencer is an illustration. And since the spiritual principle of our conscious acts is a permanent principle which abides throughout all of them, thus explaining the unity of the individual human consciousness, those who conceive substance in general after the model of the Ego, naturally conceive it as an essentially stable subject of incessant and evanescent processes.
But it is quite arbitrary thus to conceive the Ego as the sole type of substance. Bodies are substances as well as spirits, matter as well as mind. And the permanence of corporeal substances is merely relative. Nevertheless they are really substances. The relative stability of spirit which is immortal, and the relative instability of matter which is corruptible, have nothing to do with the substantiality of either. Both alike are substances, for both alike have that mode of being which consists in their existing in themselves, and not by inhering in other things as accidents do.
(e) Spencer's conception of substance as the permanent, unknowable ground of phenomena, implies that substance is one, not manifold, and thus suggests the view of reality known as [pg 230] Monism. There is yet another mistaken notion of substance, the notion in which the well known pantheistic philosophy of Spinoza has had its origin. Spinoza appears to have given the ambiguous definition of Descartes—“Substantia est res quae ita existit, ut nulla alia re indigeat ad existendum”—an interpretation which narrowed its application down to the Necessary Being; for he defined substance in the following terms: “Per substantiam intelligo id quod est in se et per se concipitur: hoc est, id cujus conceptus non indiget conceptu alterius rei a quo formari debeat”. By the ambiguous phrase, that substance “requires no other thing for existing,” Descartes certainly meant to convey what has always been understood by the scholastic expression that substance “exists in itself”. He certainly did not mean that substance is a reality which “exists of itself,” i.e. that it is what scholastics mean by Ens a se, the Being that has its actuality from its own essence, by virtue of its very nature, and in absolute independence of all other being; for such Being is One alone, the Necessary Being, God Himself, whereas Descartes clearly held and taught the real existence of finite, created substances.[245] Yet Spinoza's definition of substance is applicable only to such a being that our concept of this being shows forth the actual existence of the latter as absolutely explained and accounted for by reference to the essence of this being itself, and independently of any reference to other being. In other words, it applies only to the Necessary Being. This conception of substance is the starting-point of Spinoza's pantheistic philosophy.
Now, the scholastic definition of substance and Spinoza's definition embody two entirely distinct notions. Spinoza's definition conveys what scholastics mean by the Self-Existent [pg 231] Being, Ens a se; and this the scholastics distinguish from caused or created being, ens ab alio. Both phrases refer formally and primarily, not to the mode of a being's existence when it does exist, but to the origin of this existence in relation to the being's essence; and specifically it marks the distinction between the Essence that is self-explaining, self-existent, essentially actual (“a se”), the Necessary Being, and essences that do not themselves explain or account for their own actual existence, essences that have not their actual existence from themselves or of themselves, essences that are in regard to their actual existence contingent or dependent, essences which, therefore, if they actually exist, can do so only dependently on some other being whence they have derived this existence (“ab alio”) and on which they essentially depend for its continuance.
Not the least evil of Spinoza's definition is the confusion caused by gratuitously wresting an important philosophical term like substance from its traditional sense and using it with quite a different meaning; and the same is true in its measure of the other mistaken notions of substance which we have been examining. By defining substance as an ens in se, or per se stans, scholastic philosophers mean simply that substance does not depend intrinsically on any subjective or material cause in which its actuality would be supported; they do not mean to imply that it does not depend extrinsically on an efficient cause from which it has its actuality and by which it is conserved in being. They assert that all created substances, no less than all accidents, have their being “ab alio” from God; that they exist only by the Divine creation and conservation, and act only by the Divine concursus or concurrence; but while substances and accidents are both alike dependent on this extrinsic conserving and concurring influence of a Divine, Transcendent Being, substances are exempt from this other and distinct mode of dependence which characterizes accidents: intrinsic dependence on a subject in which they have their actuality.[246]
When we say that substance exists “in itself,” obviously we do not attach to the preposition “in” any local signification, as a part existing “in” the whole. Nor do we mean that they exist “in” themselves in the same sense as they have their being “in” God. In a certain true sense all creatures exist “in” God: In ipso enim vivimus, et movemur, et sumus (Acts xxii., [pg 232] 28), in the sense that they are kept in being by His omnipresent conserving power. But He does not sustain them as a subject in which they inhere, as substance sustains the accidents which determine it, thereby giving expression to its concrete actuality.[247] By saying that substance exists “in itself” we mean to exclude the notion of its existing “in another” thing, as an accident does. And this we shall understand better by examining a little more closely this peculiar mode of being which characterizes accidents.
65. The Nature of Accident. Its Relation to Substance. Its Causes.—From all that has preceded we will have gathered the general notion of accident as that mode of real being which is found to have its reality, not by existing in itself, but by affecting, determining, some substance in which it inheres as in a subject. What do we mean by saying that accidents inhere in substances as their subjects? Here we must at once lay aside as erroneous the crude conception of something as located spatially within something else, as contained in container, as e.g. water in a vessel; and the equally crude conception of something being in something else as a part is in the whole, as e.g. an arm is in the body. Such imaginations are wholly misleading.
The actually existing substance has its being or reality; it is an actual essence. Each real accident of it is likewise a reality, and has an essence, distinct from that of the substance, yet not wholly independent of the latter: it is a determination of the determinable being of the substance, affecting or modifying the latter in some way or other, and having no other raison d'être than this rôle of actualizing in some specific way some receptive potentiality of the concrete substance. And since its reality is thus dependent on that of the substance which it affects, we cannot ascribe to it actual essence or being in the same sense as we ascribe this to substance, but only analogically[248] ([2]). Hence scholastics commonly teach that we ought to conceive an accident rather as an “entity of an entity,” “ens entis,” than as an entity simply; rather as inhering, indwelling, affecting (in-esse) some subject, than simply as existing itself (esse); as something whose essence is rather the determination, affection, modification of an essence than itself an essence proper, the term “essence” designating properly only a substance: accidentis esse est inesse.[249] This [pg 233] conception might, no doubt, if pressed too far, be inapplicable to absolute accidents, like quantity, which are something more than mere modifications of substance; but it rightly emphasizes the dependence of the reality of accident on that of substance, the non-substantial and “diminished” character of the “accident”-mode of being; it also helps to show that the “inherence” of accident in substance is a relation—of determining to determinable being—which is sui generis; and finally it puts us on our guard against the errors that may be, and have been, committed by conceiving accidents in the abstract and reasoning about them apart from their substances, as if they themselves were substances.
This “inherence” of accident in substance, this mode of being whereby it affects, determines or modifies the substance, differs from accident to accident; these, in fact, are classified into suprema genera by reason of their different ways of affecting substance ([60]). To this we shall return later. Here we may inquire, about this general relation of accident to substance, whether it is essential to an accident actually to inhere in a substance, if not immediately, then at least through the medium of some other accident. We suggest this latter alternative because as we shall see presently there are some accidents, such as colour, taste, shape, which immediately affect the extension of a body, and only through this the substance of the body itself. Now the ordinary course of nature never presents us with accidents except as inhering, mediately or immediately, in a substance. Nor is it probable that the natural light of our reason would ever suggest to us the possibility of an exception to this general law. But the Christian philosopher knows, from Divine Revelation, that in the Blessed Eucharist the quantity or extension of bread and wine, together with the taste, colour, form, etc., which affect this extension, remain in existence after their connatural substance of bread and wine has disappeared by transubstantiation. In the [pg 234] supernatural order of His providence God preserves these accidents in existence without a subject; but in this state, though they do not actually inhere in any substance, they retain their natural aptitude and exigence for such inherence. The Christian philosopher, therefore, will not define accident as “the mode of being which inheres in a subject,” but as “the mode of being which in the ordinary course of nature inheres in a subject,” or as “the mode of being which has a natural exigence to inhere in a subject”. It is not actual inherence, but the natural exigence to inhere, that is essential to an accident as such.[250]