11 NOTES. 



relation subsisting between the achievements of Newton and Kepler, must, I 

 think, show without doubt that I do not confound together the discovery 

 of natural laws, and the interpretation, i. e. the explanation, of phenomena. 

 I say of Kepler (p. 310) "The rich supply of exact observations which were 

 furnished by Tycho Brahe, laid the foundation of the discovery of those uu- 

 changing laws of the planetary movements which prepared for Kepler 

 imperishable fame, and which, when interpreted by Newton, and shown by 

 him to be theoretically necessary, were transferred to the bright domain of 

 thought, and became the intelligent recognition of Nature" of Newton 

 (p. 351) "We terminate with the figure of the Earth as then recognised 

 from theoretical considerations. Newton attained to the explanation of the 

 system of the Universe, because he succeeded in discovering the Force of whose 

 operation the Keplerian laws are the necessary consequences." See on this 

 subject the excellent remarks " On Laws and Causes," contained in Sir Johu 

 Herschel's Address at the Fifteenth Meeting of the British Association, held 

 at Cambridge, 1845, p. xlii. ; and the Edinburgh Review, Vol. Ixxxvii. 1848, 

 p. 180183. 



( ) p. 11. In the remarkable passage in which Aristotle (Metaph. xii. 8, 

 p. 1074, Bekker) speaks of the " fragments of an early knowledge orice 

 discovered and subsequently lost," there occurs a passage of much im- 

 port, indicating freedom from the Deification of natural forces or powers, 

 personified under the forms of various divinities resembling human beings : 

 he says "Much has been added mythically for the sake of persuading the 

 multitude, as well as for the support of the laws and other useful objects." 



( u ) p. 11. The important difference between these directions, Tgdiroi, in 

 Natural Philosophy, is clearly indicated in Aristot. Phys. Auscult. i. 4, p. 187, 

 Bekker. Comp. Brandis, in the Rhein. Museum fur Philologie, Jahr. iii. 

 S. 105. 



(is) p. 12. Kosmos, Bd. i. S. 139 and 405, Note 59 ; Bd. ii. S. 348 and 

 501, Note 27 (English edition, Vol. i. p. 124, and Note 89; Vol. ii. p. 308, 

 and Note 467). A remarkable passage of Sirnplicius (p. 491) opposes in 

 the clearest manner the centripetal force to the centrifugal force : it speaks of 

 " the heavenly bodies not falling where the centrifugal force preponderate 

 over the proper falling force that which draws them downwards." On the 

 same account, in Plutarch de Facie in Orbe Lunse, p. 923, the moon is com- 

 pared, in respect to its not falling towards the Earth, to " the stone in the 

 sling." Respecting the proper signification of the irepix^pfifis of Anax'agoras, 

 vide Schaubach, in Auaxag. Clazom. IVagm. 1827, p. 107109. 



