MEMOIR OF ARISTOTLE. 95 



(about 37,000 miles) from the variation of horizon 

 consequent on a slight change of our position on its 

 surface.* But in most other respects, his views 

 partook of the current errors of antiquity. The earth, 

 he concluded, must be at rest, and therefore formed 

 the centre of the universe. That the whole hea- 

 vens were spherical, he supposed to be a necessary 

 consequence of the perfection belonging to them : 

 a solid being the most perfect mathematical dimen- 

 sion, since angular bodies would necessarily imply 

 vacuities in space. 



The revolutions of the celestial bodies he con- 

 ceived to be performed, not in consequence of a ten- 

 dency to the centre, but of the absence of any such 

 tendency ; a principle directly opposite to that of 

 modern astronomy. That they do not revolve in 

 themselves, he considered to be evident from the 

 fact, that the moon always presents the same side to 

 the earth. Their motion, therefore, resulted from 

 being carried round by revolving spheres ; the first in 

 order being that in which the fixed stars are placed, 

 next the five planets, then the sun, and lastly the 

 moon nearest to the earth. This idea of the stars 

 revolving in solemn silence, was contrary to the 



* It is curious how nearly Aristotle approached, but on a 

 different principle, to Columbus's notion of a western passage 

 to India. In his book De Cce/o, he observes, " those who 

 supposed the region about the columns of Hercules (Gibral- 

 tar) conjoined with that of India, and the sea to be thus one 

 mass, seem to conceive what is not very incredible ; alleging 

 as they did in evidence of their conclusions, that elephants 

 were found at both extremities/ 4 * 



