The eleventh, twelfth, and thirteenth contradictions which it corrects.to popular knowledge; now it controverts the contradictions incident to popular thinking, laying down the distinction between knowing and thinking, presentation and representation, which is described in the Epistem., Prop. XI., Obs. 2. The three contradictions embodied in Counter-propositions XI. XII. XIII., and corrected by the corresponding propositions, are introduced lest the student should suppose that thought is competent to perform what knowledge is inadequate to overtake. This opinion is loosely entertained by ordinary thinking, and formally adopted by psychology; and therefore it was necessary to controvert it expressly. This refutation is effected by Propositions XI. XII. XIII., which form one group or family.
The remaining contraditions which it corrects.18. The contradictions which prevail on the subject of "the phenomenal and the substantial in cognition," "the relative and the absolute in cognition"—errors which originate wholly, although remotely, in the fundamental contradiction expressed in Counter-proposition I., and which enjoy the special advocacy of psychology—are corrected in Propositions XIV. XV. XVI. XVII. XVIII. XIX. XX. XXI. And Proposition XXII., with which the epistemology concludes, has for its object the separation of the necessary laws (to which expression is given in the twenty-one preceding propositions) from the contingent laws of cognition. The main purpose of Pro-