2. We cannot hope to vanquish this difficulty unless we face it boldly from the first. There are in the old-fashioned Logic-books tricks and puzzles, fallacies and repartees, which can in some degree be made amusing; but of these I do not intend to speak. The course by which alone I can hope honestly to awaken a true logical interest among any who may be quite unfamiliar with the subject, is to approach the matter descriptively, and try to set before you fully and fairly what the problem is which the process of knowledge has to meet. And then it may be possible to claim a genuine theoretical curiosity--none the less genuine that it may be tinged with a sympathy for man’s common birthright of intelligence--for the detailed explanation of the means by which this problem is solved from day to day. Such an explanation is the science of Logic. The problem may be thus introduced. Several of those present have, I believe, attended a previous course of lectures on Psychology. They have learned, I presume, to think of the mind as the course of consciousness, a continuous connected presentation, more or less emphasising within it various images, and groups of images and ideas, which may be roughly said to act and re-act upon each other, to cohere in systems, and to give rise to the perception of self. This course of consciousness, including certain latent elements, the existence of which it is necessary to assume, is an individual mind, attached to a particular body, and so far as we know, not separable from the actions and affections of that body. What is the connection between such a course of consciousness in any individual, and the world as that individual knows and wills it? This is the point at {4} which Psychology passes into Logic. Psychology treats of the course of ideas and feelings; Logic of the mental construction of reality. How does the course of my private ideas and feelings contain in it, for me, a world of things and persons which are _not merely in my mind_? _World as Idea_ 3. Schopenhauer called his great work, _The World as Will and Idea_. [1] Leaving out Will for the moment, let us consider the world “as Idea.” “‘The world is my idea;’ [2] this is a truth which holds good for everything that lives and knows, though man alone can bring it into reflective and abstract consciousness. If he really does this, he has attained to philosophical wisdom. It then becomes clear and certain to him that what he knows is not a sun and an earth, but only an eye that sees a sun, a hand that feels an earth; that the world which surrounds him is there only as an idea, _i.e._ only in relation to something else, the consciousness which is himself. If any truth can be asserted _a priori_, it is this; for it is the expression of the most general form of all possible and thinkable experience: a form which is more general than time, space, or causality, for they all pre-suppose it. .....