Page:History of Modern Philosophy (Falckenberg).djvu/117

 PRINCIPLES OF THE SYSTEM. 95 this definition, there is but one substance, God, who, as causa siii, has absolutely no need of any other thing in order to his existence, was announced by Descartes himself. If created substances are under discussion, the term does not apply to them in the same sense (not univoce) as when we speak of the infinite substance ; created beings require a different explanation, they are things which need for their existence only the co-operation of God, and have no need of one another. Subst ance is cognized through its qualities, among whi c h one is pr e-eminent from the fact that it expressjgs the essence or nature of the tTiThg, andthat it is conceived through itself, without the aid of the others , while they presupp ose it and ca nnot be thought without it. The former fundamental properties are termed attribut es, and these secondary ones, modes or accidents. Position, figure, motion, are contingent properties of body ; they pre- suppose that it is extended or spatial ; they are modi exten- sionis, as feeling, volition, desire, representation, and judg- ment are possible only in a conscious being, and hence are merely modifications of thought. Extension is the essen- tial or constitutive attribute of body, and thought of mind. Body is never without extension, and mind never without thought — mens semper cogitat. Guided by the self-evident principle that the non-existent has no properties, we argue from a perceived quality to a substance as its possessor or support. Substances are distinct from one another when we can clearly and distinctly cognize one without the other. Now, we can adequately conceive mind without a corporeal attribute and body without a spiritual one; the former has nothing of extension in it, the latter nothing of thought : hence thinking substance and extended substance are entirely distinct and have nothing in common. Matter and mind are distinct realiter, matter and extension idealiter merely. Thus we attain three clear and distinct ideas, three eternal verities : substantia infinita sive deus, substantia Jinit a cogitans sive mens, substantia extensa sive corpus. By this abrupt contraposition of body and mind as re- ciprocally independent substances, Descartes founded that dualism, as whose typical representative he is still honored or opposed. This dualism between the material and spiritual