3. _The Physics of Newton._ To his university training Kant was indebted also for his acquaintance with Newton. The antagonism between the metaphysics of Wolff and the physics of Newton was, at least at the beginning of Kant’s career, of decisive importance in his development. One of Kant’s teachers at the university was Martin Knutzen, whose lectures included philosophy, mathematics, and natural science. Through personal intercourse with Knutzen, the young Kant was introduced to the Wolffian philosophy, and also to the Newtonian mathematics and physics. During his activity as a teacher Kant showed, even into his later period, a predilection for natural science, especially for physical geography and anthropology. The same year in which he entered upon his career as teacher in the University of Königsberg (1755), he published his celebrated _Theory of the Heavens_, in which he anticipated Laplace by forty years in the formulation of the nebular hypothesis. 4. _The Humanitarianism of Rousseau._ Kant got from Rousseau a new evaluation of man. Kant had the advantage of a prolonged youthful development. He was well into his thirties when the movement, begun by Lessing, became a social force in Germany. A new political consciousness appeared among the German people, due to the influence of Frederick the Great and to that of the Frenchmen, Voltaire and Rousseau. Kant was thirty-eight (in 1762) when he read Rousseau’s _Emile_. Kant had been brought up in the common teaching of the early part of the Enlightenment to despise the ignorant masses of people. Through Rousseau he received in words of authority the conception of the inherent dignity of the individual man. Through this conception science and speculation came to have a new value to Kant. They were no longer ends in themselves, but the means for moral development. The moral in its primacy over the intellectual came to be a permanent feature in Kant’s doctrine. His early Pietism was confirmed, and Rousseau replaced Newton in his regard. 5. _The Skepticism of Hume._ The influence of Hume’s skepticism was felt by Kant just before his eleven years of silence, when he became engaged in his construction of his critical problem. But Hume influenced Kant in a negative way. The classic and oft-quoted expression of Kant, that Hume awoke him from his “dogmatic slumber,” refers to the dogmatism of the empirical school to which Hume belonged, and not to that of the rationalistic school of Wolff. To Kant both empiricism and rationalism were dogmatic; the one because it assumed the validity of sensations, the other because it assumed the existence of innate ideas. Thus Hume effected a reaction in Kant against Hume’s own doctrine. But in thus reacting from Hume, Kant saw that the answer was to be found not in the rationalism of Wolff, but in an ideal conception of space and time. Hume’s influence was the last before Kant firmly established his theory of knowledge in his _Critique of Pure Reason_.