542 THE POPULAR SCIENCE MONTHLY 



one of his university teachers, Knutzen, professor of logic and meta- 

 physics at Koenigsberg, who was at once an ardent Pietist, an ardent 

 Wolffian, and an ardent Newtonian. All of the earliest three consid- 

 erable writings 6 of Kant may be said to be chiefly attempts to give new 

 applications to Newton's principles, or to supply his omissions, or to do 

 both at once. Of these three, the treatise with which we are here con- 

 cerned, the "Allgemeine Naturgeschichte " of 1755, was an endeavor 

 to fill up two of the most obvious gaps (from the cosmical system- 

 maker's point of view) which the author of the " Principia " had left. 

 It required no great originality and no stroke of genius on Kant's part 

 to recognize these gaps and to devise the general outlines of the hypoth- 

 eses by which he tried to fill them. The problems, and in one of the two 

 cases at least, the proposed solution even in most of its details, were 

 present in the scientific atmosphere of the period as epidemic infec- 

 tions. 



The first of these gaps, and the one less pertinent to our present 

 topic, lay in Newton's failure to suggest even a conjectural hypothesis 

 concerning the systematic arrangement of the heavenly bodies beyond 

 the boundaries of our system. To three of his disciples at almost the 

 same time 7 — but to the two others at an earlier date than to Kant — it 

 occurred as a " probable," though perhaps not strictly verifiable, suppo- 

 sition that our group of planets with its central sun is only a part of an 

 analogous but larger concentric system of revolving bodies, or of similar 

 groups of bodies, constituting the Milky Way; and that this in turn is 

 but part of a single, universal system, all the members of which are 

 similarly arranged with respect to one another, and revolve about a 

 body at the center of gravitation of the entire universe in accordance 

 with Newton's laws. The hypothesis had, of course, an attractive com- 

 bination of grandiosity and simplicity; and it was natural enough to 

 inquire whether or not it were true. But it was, I suppose, essentially 

 incapable of any serious testing by any data then in the possession of 

 astronomers. It is apparently only within the past five years that some 

 light has been thrown upon the problem of a possible " systematic ar- 

 rangement " of the fixed stars ; 8 and the arrangement which recent re- 



8 " On the True Mode of Estimating Vis Viva," 1747 ; " Universal Natural 

 History and Theory of the Heavens," 1755 ; " Physical Monadology," 1756. 



7 To Thomas Wright, of Durham, before 1750; to Lambert, 1749; and to 

 Kant. Wright's " Original Theory or New Hypothesis of the Universe, founded 

 upon the Laws of Nature and solving by Mathematical Principles the General 

 Phenomena of the Visible Creation," London, 1750, was known to Kant through 

 a summary in the Hamburg Freie Urteile, 1751, and is referred to by him in 

 the " Allgemeine Naturgeschichte." Lambert's " Kosmologische Briefe " were 

 not published until 1761, but were planned and partly written in 1749, as Lam- 

 bert declares in a letter to Kant, November 13, 1765. 



8 See the article of Eddington on "Star-Streams," in Scientia, VIII., 1910, 

 p. 40. 



