Kant’s outward life was less eventful and less changeful than his philosophical development.[1] Born in Koenigsberg in 1724, the son of J.G.  Cant, a saddler of Scottish descent, his home and school training were both strict and of a markedly religious type.  He was educated at the university of his native city, and for nine years, from 1746 on, filled the place of a private tutor.  In 1755 he became Docent, in 1770 ordinary professor in Koenigsberg, serving also for six years of this time as under-librarian.  He seldom left his native city and never the province.  The clearness which marked his extremely popular lectures on physical geography and anthropology was due to his diligent study of works of travel, and to an unusually acute gift of observation, which enabled him to draw from his surroundings a comprehensive knowledge of the world and of man.  He ceased lecturing in 1797, and in 1804 old age ended a life which had always, even in minute detail, been governed by rule.  A man of extreme devotion to duty, particularity, and love of truth, and an amiable, bright, and witty companion, Kant belongs to the acute rather than to the profound thinkers.  Among his manifold endowments the tendency to combination and the faculty of intuition (as the Critique of Judgment especially shows) are present to a noticeable degree, yet not so markedly as the power of strict analysis and subtle discrimination.  So that, although a mediating tendency is rightly regarded as the distinguishing characteristic of the Kantian thinking, it must also be remembered that synthesis is everywhere preceded by a mighty work of analysis, and that this still exerts its power even after the adjustment is complete.  Thus Kant became the energetic defender of a qualitative view of the world in opposition to the quantitative view of Leibnitz, for which antitheses (e.g., sensation and thought, feeling and cognition, good and evil, duty and inclination) fade into mere differences of degree.

[Footnote 1:  The following have done especially valuable service in the investigation of the development of Kant’s doctrine:  Paulsen (Versuch einer Entwickelungsgeschichte der Kantischen Erkenntnisstheorie, 1875), B. Erdmann, Vaihinger, and Windelband.  Besides Hume and Leibnitz, Newton, Locke, Shaftesbury, Rousseau, and Wolff exercised an important influence on Kant.]

In the beginning of this chapter we have indicated how the new ideal of knowledge, under whose banner Kant brought about a reform of philosophy, grew out of the conflict between the rationalistic (dogmatic) and the empirical (skeptical) systems.  This combines the Baconian ideal of the extension of knowledge with the Cartesian ideal of certainty in knowledge.  It is synthetic judgments alone which extend knowledge, while analytic judgments are explicative merely.[1] A priori judgments alone are perfectly certain, absolutely universal, and necessarily valid; while a posteriori judgments are subjectively valid merely, lack necessity, and, at best, yield only relative universality.[2] All analytic judgments are a priori, all empirical or a posteriori judgments are synthetic.  Between the two lies the object of Kant’s search.  Do synthetic judgments a priori exist, and how are they possible?