We have now reached an action of mind, a faculty, whose existence is strenuously denied. Most able and thorough thinkers, patient inquirers within the field of philosophy itself, with a host of scientific investigators, who bring with them predilections and reasonings suited to other departments, regard this furniture of intuitive ideas as wholly fabulous, as an unnecessary assumption in the explanation of phenomena entirely intelligible without it Yet there is in philosophy no point of more importance, of more wide-reaching influence than this. there is in the intellectual handling of the facts of the world revealed in perception and consciousness, a new power of mind, which we term the reason, furnishing rational ideas and grounds of procedure, and enabling the judgment to operate on the otherwise limited, stubborn, irreducible sensations present. The existence and office of a portion of these ideas all philosophers admit; they are at variance only as to their source and nature-a variance which leads to the denial of the remaining and most essential ones. The notions of space and of time, traced to an empirical source, prepares the way for a denial of right and liberty in their transcendent character. We shall now proceed to take up these ideas one by one. both to establish the whole class and each member of it singly.