Page:Encyclopædia Britannica, Ninth Edition, v. 13.djvu/883

KANT 847 The early writings of Kant are almost without exception on questions of physical science. It was only by degrees that philosophical problems began to engage his attention, and that the main portion of his literary activity was turned towards them. It will be convenient, therefore, in enumerating the varied writings of Kant, to place in a separate group those which bear directly on physical science. The following are the most important in this group : 1. Thoughts on the True Estimate of Vis Viva, 1747: an essay dealing with the famous dispute between the Cartesians and Leibnitzians regarding the expression for the amount of a force. According to the Cartesians, this quantity was directly proportional to velocity ; according to their opponents, it varied with the square of the velocity. The dispute has now lost its interest, for physicists have learned to distinguish accurately the two quantities which are vaguely included under the expression amount of force, and conse quently have been able to show in what each party was correct and in what it was in error. Kant s essay, with some fallacious explana tions and divisions, criticizes acutely the arguments of the Leibnitzians, and concludes with an attempt to show that both modes of expression are correct when correctly limited and interpreted. 2. Whether the Earth in its Revolution IMS experienced some Change since the Earliest Times, 1754. In this brief essay Kant throws out a notion which has since been carried out, in ignorance of Kant s priority, by Delaunay (1865) and Adams. He points out that the action of the moon in raising the waters of the earth must have a secondary effect in the slight retardation of the earth s motion, and refers to a similar cause the fact that the moon tarns always the same face to the earth. 3. General History and Theory of the Heavens (" Allgemeine Natur- Geschichte und Theorie des Himmels "), published anonymously in 1755. In this remarkable work Kant, proceeding from the Newtonian conception of the solar system, extends his consideration to the entire sidereal system, points out how the whole may be mechanically regarded, and throws out the important speculation which has since received the title of the nebular hypothesis. In some details, such, e.g. , as the regarding of the motion of the entire solar system as portion of the general cosmical mechanism, he had predecessors, among others J. Wright of Durham, but the work as a whole contains a wonderfully acute anticipation of much that was afterwards carried out by Herschel and Laplace. The hypothesis of the original nebular condition of the system, with the consequent explanation of the great phenomena of planetary formations and movements of the satellites and rings, is unquestionably to be assigned to Kant. 4. Brief Account of some Thoughts on Fire ("Meditationum quarun- dam de Igne succincta delineatio "), 1755 : an inaugural dissertation, containing little beyond the notion that bodies operate on one another through the medium of a uniformly diffused, elastic, and subtle matter (ether) which is the underlying substance of heat and light. Both heat and light are regarded as vibrations of this diffused ether. 5. On the Causes of Earthquakes, 1755 ; Description of the Earth quake of 1755, 1756 ; Consideration of some Recently Experienced Earthquakes, 1756. 6. Explanatory Remarks on the Tlicory of the Winds, 1756. In this brief tract, Kant, apparently in entire ignorance of the explana tion given in 1735 by Hadley, points out how the varying velocity of rotation of the successive zones of the earth s surface furnishes a key to the phenomena of periodic winds. His theory is in almost entire agreement with that now received. See the parallel statements from Kant s tract and Dove s essay on the influence of the rotation of the earth on the flow of its atmosphere, 1835, given in Zollner s work, Ueber die Natur der Cometen, pp. 477-482. 7. On the Different Races of Men, 1775 ; Determination of the Notion of a Human Race, 1785 ; Conjectural Beginning of Human History, 1786 : three tracts containing some points of interest as regards the empirical grounds for Kant s doctrine of teleology. Reference will be made to them in the notice of the Kritik of Judgment. 8. On the Volcanoes in the Moon, 1785 ; On the Influence of the Moon on the Weather, 1794. The second of these contains a remarkable discussion of the relation between the centre of the moon s figure and its centre of gravity. From the difference between these Kant is led to conjecture that the climatic conditions of the side of the moon turned from us must be altogether unlike those of the face presented to us. His views have been restated by Hansen. 9. Lectures on Physical Geography, 1822 : published from notes of Kant s lectures, with the approval of the author. Consideration of these works is sufficient to show that Kant s mastery of the science of his time was complete and thorough, and that his philosophy is to be dealt with as having throughout a reference to general scientific conceptions. For more detailed treatment of his importance in science, reference may be made to Zollner s essay on "Kant and his Merits on Natural Science" contained in the .work on the Nature of Comets (pp. 426-484) ; to Dietrich, Kant and Newton ; to Schultze, Kant and Darwin ; and to Reuschle s careful analysis of the scientific works in the Deutsche Viertcljahrs-schrift, 1868. The notice of the philosophical writings of Kant need not be more than bibliographical, as in the account of his philosophy it will be necessary to consider at some length the successive stages in the development of his thought. Arranged chronologically these works are as follows : 1755. Principiorum Primorum cognitionis Mctaphysicse nova Dilucidatio. 1756. Metaphysics^ cum geometria junctse usus in philosophia naturali, cujus Specimen I. continct Monadologiam Physicam. 1762. Diefalsche Spitzfindigkcit der vicr syllogistischcn Figurcn, "The False Subtlety of the Four Syllogistic Figures." 1763. Versuch den Begriff der ncgativen Grossen in die JVclt- weisheit einzufiihren, "Attempt to introduce the Notion of Nega tive Quantities into Philosophy." 1763. Der einzig mogliche Bcweisgrund zu einer Demonstration des Daseins Gottcs, " The only possible Foundation for a Demon stration of the Existence of God." 1763. Untersuchung ilber die Dcutlichkcit der Grundsdtze der natiirlichcn Theologie und Moral, " Essay on the Evidence (Clear ness) of the Fundamental Propositions of Natural Theology and Ethics." 1766. Trdume eincs Geistcrsehers, crldutcrt durch Trdume der Mctaphysik, "Dreams of a Ghost-seer (or Clairvoyant), explained by the Dreams of Metaphysic. " 1768. Von dem crsten Grunde des Unterschiedcs der Gcgenden im Rdumc, " Foundation for the Distinction of Positions in Space." The above may all be regarded as belonging to the precritical period of Kant s development. The following introduce the notions and principles characteristic of the critical philosophy. 1770. De Mundi Sensibilis et Intel ligibil is forma et principiis. 1781. Kritik der reinen Vernunft, " Kritik of Pure Reason." 1783. Prolegomena zu einer jedcn kiinftigen Mctaphysik die als Wissenschaft wird auftrctcn konnen, " Prolegomena to all Future Metaphysic which may present itself as Science." 1784. Idee zu einer allgcmcinen Geschichte im wcltburgcrlichcr Absicht, " Notion of a Universal History in a Cosmopolitan Sense." With this may be coupled the review of Herder in 1785. 1785. Grundlegung der Mctaphysik der Sittcn, "Foundations of the Metaphysic of Ethics. " 178G. Metaphysisclie Anfangsgriinde der Natur wisscnschaft, "Metaphysical Elements of Natural Science." 1788. Ucber den Gcbrauch tclcologischcr Principun in der Philo sophic, "On the Employment of Ideological Principles in Philosophy." 1788. Kritik der praktisrhen Vernunft, " Kritik of Practical Reason." 1790. Kritik der Urthcilskraft, " Kritik of Judgment." 1790. Ueber eine Entdcckung, nach der alle neue Kritik der reinen Vernunft durch eine dltere entbehrlich gcmacht werdcn soil, "On a Discovery by which all the recent Critique of Pure Reason is superseded by a more ancient (i.e., by Leibnitz s philosophy)." 1791 . Ueber die loirklichcn Fortschittc der Mctaphysik se.it Leibnitz und Wolff, "On the Real Advances of Metaphysics since Leibnitz and Wolff. " 1794. Die Religion innerhalb der Grenzcn der blosscn Vernunft, " Religion within the Bounds of Reason only." 1794. Ucber Philosophic ilbcrhaupt, "On Philosophy generally." 1797. Metaphysisclie Anfangsgriinde der Rcchtslchrc, and Mcta- physische Anfangsgriinde der Tugendlchre. 1798. Der Streit der Facultdtcn, " Contest of the Faculties." 1798. Anthropologic. The Kantian Philosophy. Historians are accustomed to divide the general current of speculation into epochs or periods marked by the dominance of some single philosophic conception with its systematic evolution. Per haps in no case is the character of an epoch more clearly apparent than in that of the critical philosophy. The great work of Kant absolutely closed the lines of speculation along which the philosophi cal literature of the 18th century had proceeded, and substituted for them a new and more comprehensive method of regarding the essen tial problems of thought, a method which has prescribed the course of philosophic speculation in the present age. The critical system has thus a twofold aspect. It takes up into itself what had characterized the previous efforts of modern thought, shows the imperfect nature of the fundamental notions therein employed, and offers a new solution of the problems to which these notions had been applied. It opens up a new series of questions upon which subsequent philosophic reflexion has been directed, and gives to them the form, under which it is possible that they should be