With these considerations, we have answered the question concerning the relation between the History of Logic and the History of Philosophy. This relation is the same as that between Logic and Philosophy,—terms which are capable neither of distinction nor of opposition. The history of Logic is not outside the history of Philosophy, but is an integral part of this history itself. To make it the object of special treatment always means to compose a complete history of philosophy, in which, from the literary point of view, prominence and priority are given to the problems of Logic, the others being thrown, not outside the picture, but into the background. The same may be said of the History of Æsthetic or of Ethic or of any other particular discipline, which is never held to be distinguishable.
Works relating to the history of Logic.
Logic being more or less profoundly renovated (as we have sought to do in this book), it is natural that the histories of Logic hitherto available can no longer be completely satisfactory. For they are written from points of view that have been surpassed, such as Aristotelian formalism or Hegelian panlogism, and therefore either do not interpret facts with exactitude, or they give prominence and exaggerated importance to certain orders of facts, neglecting others far more worthy of mention and of examination.
Of the special books bearing the title of the History of Logic, there is really only one—that of Charles Prantl—which, based upon wide researches, is truly remarkable for its doctrine and for lucid and animated exposition. Unfortunately this does not go further than the fifteenth century and omits the whole movement of modern philosophy.[1] But even the period exhaustively treated by him (Antiquity and the Middle Ages) is looked at from the narrow angle of an Aristotelian and formal temperament. Other works bearing the same title are not worthy of attention.[2] On the other hand, the better histories of Logic must not be sought under this title, but especially in the better Histories of Philosophy, beginning with that of Hegel, which, for the most part, is precisely a history of Logic.
In inaugurating a new treatment, governed by the principles which we have defended, we shall confine ourselves, in the following pages, to a sketch of the history of some of the principal parts of logical doctrine, without any claim to even approximate completeness, and with a view to giving simple illustrations of the things that were said in the theoretical part. In this theoretical part, in virtue of the identity of philosophy and history which we have explained, history may be said to be already contained and projected, even though names and dates are mostly omitted and left to be understood.
[1] Geschichte der Logik im Abendlande, Leipzig, 1855-1870, 4 vols. Scattered memoirs of certain writers belonging to later times are being published by Prantl in academic journals, and it would be opportune to collect these in a volume.
[2] A rapid sketch, compiled in part from the work of Prantl, with a polemical addition directed against the adversaries of the Hegelian Logic, precedes the Logic2 of Kuno Fischer. The historical part of the System der Logik of Ueberweg (fifth edition, 1882, edited by J. B. Meyer) has an almost exclusively bibliographical character with excerpts, and that contained in L. Rabus, Logik ii. System der Wissenschaften, Erlangen-Leipzig, 1895, is yet more arid. The Gesch. d. Logik of F. Harms (Berlin, 1881) is meagre in facts, verbose and vague. In recent monographs on special points, one feels the effect of what is called Logistic or new formalism, which makes the authors pursue ineptitudes and curiosities of slight value.