Substance

Substance is a term which has played a great part in philosophical and theological discussion. It occurs first in the Aristotelian enumeration of categories, where ousia is in a manner opposed to the other nine categories of attribution and relation. This contrast is expressed in the correlation of the Latin terms substance and accident. Substance is defined as that which exists per se, whereas attributes or accidents exist in alio. The substance, in other words, is regarded as an independent existence, a permanent subject of which the accidents are predicated, and to which they belong as its qualities or states. Individual things were thus treated by Aristotle and the scholastics as existing per se; they are, in the Aristotelian phrase, 'the first substances.' To the objection which readily occurs that God alone is in this sense substance—i.e. truly self-subsistent—they replied by the distinction between per se and a se. If the world is not to be resolved into a flux of accidents, created substances must exist per se; but God alone exists a se or absolutely. The same distinction—between created substances and God as the one absolutely independent substance—reappears in Descartes, but is repudiated by Spinoza, who thus reaches his completely pantheistic doctrine of the unica substantia. In English philosophy the aspect of substance made most prominent is that of an underlying 'substratum' (the Greek ὑποκείμενον) or unknown 'support' of the qualities we know. Locke, like Descartes, believed in two classes of substances, material and spiritual; but the negative criticism of Berkeley was brought to bear against the first class, while Hume directed the same battery against the spiritual substances which the bishop had spared, and thus pulverised the world into unsupported accidents. All our perceptions, Hume declares, 'may exist separately, and have no need of anything else to support their existence.' The criticism, however, which is valid against the peculiar form which the doctrine of substance had assumed in Locke ignores the really indispensable character of the conception. The notion of substance as something over and above the qualities—an inaccessible somewhat, hidden behind the qualities instead of being revealed by them—is undoubtedly false. But a pure phenomenalism can yield no theory of knowing or being. The world, as it has been said, is not a flight of adjectives; qualities do not fly loose; they are necessarily unified in a substance or subject. In recent philosophy the misleading idea of a substratum reappears in the Kantian theory of the unknowable thing-in-itself, which in turn develops into the characteristic doctrine of modern agnosticism.