Now in reference to this Idea, I maintain that the sequence in the systems of Philosophy in History is similar to the sequence in the logical deduction of the Notion-determinations in the Idea. I maintain that if the fundamental conceptions of the systems appearing in the history of Philosophy be entirely divested of what regards their outward form, their relation to the particular and the like, the various stages in the determination of the Idea are found in their logical Notion. Conversely in the logical progression taken for itself, there is, so far as its principal elements are concerned, the progression of historical manifestations; but it is necessary to have these pure Notions in order to know what the historical form contains. It may be thought that Philosophy must have another order as to the stages in the Idea than that in which these Notions have gone forth in time; but in the main the order is the same. This succession undoubtedly separates itself, on the one hand, into the sequence in time of History, and on the other into succession in the order of ideas. But to treat more fully of this last would divert us too far from our aim. I would only remark this, that what has been said reveals that the study of the history of Philosophy is the study of Philosophy itself, for, indeed, it can be nothing else. Whoever studies the history of sciences such as Physics and Mathematics, makes himself acquainted with Physics and Mathematics themselves. But in order to obtain a knowledge of its progress as the development of the Idea in the empirical, external form in which Philosophy appears in History, a corresponding knowledge of the Idea is absolutely essential, just as in judging of human affairs one must have a conception of that which is right and fitting. Else, indeed, as in so many histories of Philosophy, there is presented to the vision devoid of idea, only a disarranged collection of opinions. To make you acquainted with this Idea, and consequently to explain the manifestations, is the business of the history of Philosophy, and to do this is my object in undertaking to lecture on the subject. Since the observer must bring with him the Notion of the subject in order to see it in its phenomenal aspect and in order to expose the object faithfully to view, we need not wonder at there being so many dull histories of Philosophy in which the succession of its systems are represented simply as a number of opinions, errors and freaks of thought. They are freaks of thought which, indeed, have been devised with a great pretension of acuteness and of mental exertion, and with everything else which can be said in admiration of what is merely formal. But, considering the absence of philosophic mind in such historians as these, how should they be able to comprehend and represent the content, which is reasoned thought?