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 Buch 
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 C<clo, 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.” 
