There is, perhaps, an increasing tendency to recognize that the organism of knowledge is a thing which from any single viewpoint must be seen in perspective. It is of course a postulate that all truths harmonize, but to give the harmonious whole in a projection in one plane is an undertaking whose adequacy in one sense involves an inadequacy in another. No human architect can hope to take up in succession all essential points of view in regard to the form of knowledge or to logic. "The great campanile is still to finish." BIBLIOGRAPHY.--Historical: No complete history of logic in the sense in which it is to be distinguished from theoretical philosophy in general has as yet been written. The history of logic is indeed so little intelligible apart from constant reference to tendencies in philosophical development as a whole, that the historian, when he has made the requisite preparatory studies, inclines to essay the more ambitious task. Yet there are, of course, works devoted to the history of logic proper. Of these Prantl's _Geschichte der Logik im Abendlande_ (4 vols., 1855-1870), which traces the rise, development and fortunes of the Aristotelian logic to the close of the middle ages, is monumental. Next in importance are the works of L. Rabus, _Logik und Metaphysik_, i. (1868) (pp. 123-242 historical, pp. 453-518 bibliographical, pp. 514 sqq. a section on apparatus for the study of the history of logic), _Die neuesten Bestrebungen auf dem Gebiete der Logik bei den Deutschen_ (1880), _Logik_ (1895), especially for later writers § 17. Ueberweg's _System der Logik und Geschichte der logischen Lehren_ (4th ed. and last revised by the author, 1874, though it has been reissued later, Eng. trans., 1871) is alone to be named with these. Harms' posthumously published _Geschichte der Logik_ (1881) (_Die Philosophie in ihrer Geschichte_, ii.) was completed by the author only so far as Leibnitz. Blakey's _Historical Sketch of Logic_ (1851), though, like all this writer's works, closing with a bibliography of some pretensions, is now negligible. Franck, _Esquisse d'une histoire de la logique_ (1838) is the chief French contribution to the subject as a whole.