INTRODUCTION. 66 



the consideration of phenomena which are so complicated, 

 and have, up to the present time, been found so little suscep- 

 tible of the application of rigorous method, that the physical 

 science of the earth can not boast of the same certainty and 

 simplicity in the exposition of facts and their mutual connec 

 tion which characterize the celestial portion of the Cosmos. 

 It is not improbable that the difference to which we allude 

 may furnish an explanation of the cause which, in the earliest 

 ages of intellectual culture among the Greeks, directed the 

 natural philosophy of the Pythagoreans with more ardor to the 

 heavenly bodies and the regions of space than to the earth 

 and its productions, ai?d how through Philolaiis, and subse- 

 quently through the analogous views of Aristarchus of Samos, 

 and of Seleucus of Erythrea, this science has been made more 

 conducive to the attainment of a knowledge of the true system 

 of the world than the natural philosophy of the Ionian school 

 could ever be to the physical history of the earth. Giving but 

 little attention to the properties and specific differences of 

 matter filling space, the great Italian school, in its Doric 

 gravity, turned by preference toward all that relates to meas- 

 ure, to the form of bodies, and to the number and distances of 

 the planets,* while the Ionian physicists directed their atten 

 tion to the qualities of matter, its true or supposed metamor 

 phoses, and to relations of origin. It was reserved for the 

 powerful genius of Aristotle, alike profoundly speculative and 

 practical, to sound with equal success the depths of abstraction 

 and the inexhaustible resources of vital activity pervading ine 

 material world. 



Several highly distinguished treatises on physical geography 

 are prefaced by an introduction, whose purely astronomical 

 sections are directed to the consideration of the earth ia, its 

 planetary dependence, and as constituting a part of that great 

 system which is animated by one central body, the sun. This 

 course is diametrically opposed to the one which I propose 

 following. In order adequately to estimate the dignity 01* the 

 Cosmos, it is requisite that the sidereal portion, termexl by 

 Kant the natural history of the faavens, should not be made 

 subordinate to the terrestrial. In the science of the Cosmos, 

 according to the expression of Aristarchus of Samos, the pio- 

 neer of the Copernican system, the sun, with its satellites, 

 was nothing more than one of the innumerable stars by v/hicb 

 space is occupied. The physical history of the world must, 

 therefore, begin with the description of the heavenly bodies. 

 * Compare Otfried MUller's Dorien, bd. i., s. 362. 



