48 DISSERTATION SECOND. [part i. 



scrupulous attention. On the other hand, as terrestrial ob- 

 jects were always at hand, and spontaneously falling under 

 men's view, it seemed unnecessary to take much trouble to 

 become acquainted with them, and as for applying mea- 

 sures, their irregularity appeared to render every idea of 

 such prqceeding nugatory. The Aristotelian philosophy 

 particularly favoured this prejudice, by representing the 

 earth, and all things on its surface, as full of irregularity and 

 confusion, while the principles of heat and cold, dryness 

 and moisture, were in a state of perpetual warfare. The 

 unfortunate division of motion into natural and violent, and 

 the distinction, still more unfortunate, between the proper- 

 ties of motion and of body, in the heavens and on the earth, 

 prevented all intercourse between the astronomer and the 

 naturalist, and all transference of the maxims of the one to 

 the speculations of the other. 



Though, on account of this inattention to experiment, no- 

 thing like the true system of natural philosophy was known 

 to the ancients, there are, nevertheless, to be found in their 

 writings many brilliant conceptions, several fortunate conjec- 

 tures, and gleams of the light which was afterwards to be so 

 generally diffused. 



Anaxagoras and Empedocles, for example, taught that 

 the moon shines by light borrowed from the sun, and were 

 led to that opinion, not only from the phases of the moon, 

 but from its light being weak, and unaccompanied by heat. 

 That it was a habitable body, like the earth, appears to be a 

 doctrine as old as Orpheus ; some lines, ascribed to that po- 

 et, representing the moon as an earth, with mountains and 

 cities on its surface. 



Democritus supposed the spots on the face of the moon 

 to arise from the inequalities of the surface, and from the 

 shadows of the more elevated parts projected on the plains. 

 Every one knows how conformable this is to the discoveries 

 made by the telescope. 



