PROP. I.————
other errors, are to be attributed. Throughout these Institutes a correct doctrine of the contradictory, showing distinctly what it is (namely, that it is either of the factors of cognition taken by itself or apart from its co-factor), has been developed. Philosophers have hitherto supposed that propositions alone could be contradictory: in this work their attention is directed more particularly to the consideration of contradictory terms; for these, no less than propositions, may express that which is contradictory.
Distinction between the singly and doubly contradictory.11. In further explanation of this doctrine, a distinction may here be pointed out between the singly contradictory and the doubly contradictory. The two co-factors of cognition (subject and object), when considered singulatim, or apart from each other, are only the singly contradictory,—a centreless circle, or a stick with only one end, is the doubly contradictory. To redeem any object (a stick, or a circle, or whatever it may be) from contradiction—in other words, to render it apprehensible—the subject must know itself along with it. Here only one supplementation is required—the me must be known along with the thing. But to redeem from contradiction a centreless circle or a stick with only one end, two supplementations are required: first, the centre must be supplied to the circle; and secondly, the me must, moreover, be taken into account.
