Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/416

388PROP. XXII.———— required actually to perform, but only to understand the possibility of. No man, when he apprehends or thinks of the synthesis which subsists between himself and external things, can, in point of fact, leave his senses out of the estimate, or conceive them altogether changed; but he can surely understand that they might possibly be altered; in other words, that the synthesis of himself and things might possibly embrace other modes of apprehension than his five senses. How this should be, or what these other modes of apprehension might be, he cannot of course conceive; nor is he now called upon to conceive it. All that he is required to understand is the possibility that such a change should take place without rendering the attainment of knowledge altogether inconceivable; and, at the same time, to mark the impossibility of there being any knowledge in any quarter if the element called self and the law called self-consciousness were supposed to be discounted from the process, or exchanged for any other law.

5. This, then, being premised, the reader may obtain a distinct conception of the analysis by which the contingent are distinguished from the necessary laws of cognition, by attending to the following illustration: Let him suppose himself to be looking at something—a tree, for example: he will find that the true and total object of his mind, in