PORTION OF THE COSMOS. THE PLANETS. 299 



the two planets which we call inferior planets, Mercury and 

 Venus, are regarded as satellites of the sun, which is itself 

 supposed to revolve round the Earth. There is as little 

 reason for terming such a system an Egyptian one ( 502 ) as 

 for confounding it with Ptolemy's epicycles, or Tycho Brahe's 

 view of the universe. 



The names by which the five star-like planets were desig- 

 nated by the nations of antiquity are of two kinds mytho- 

 logical or names of divinities, and significant or descriptive, 

 taken from real or supposed physical properties. It is the 

 more difficult to determine, from the only sources of infor- 

 mation hitherto open to us, what may have been derived in 

 this respect originally from the Egyptians, and what from 

 the Chaldeans, because Greek writers have handed down to 

 us not the original names themselves as they were in use 

 among other nations, but only Greek equivalents, which 

 they modified according to their own particular views. 

 What knowledge was possessed by the Egyptians before the 

 Chaldeans, and whether the latter are to be regarded merely 

 as the highly-gifted scholars of the former ( 503 ), are questions 

 which touch on the important but obscure problems of the 

 earliest civilization of the human race, and the beginning of 

 scientific development of thought on the banks of the Nile, 

 or on those of the Euphrates. Although the Egyptian 

 denominations of the 36 Decans are known, only one or 

 two of the Egyptian names of the planets have come down 

 lo us ( 504 ). 



It is remarkable that the mythological names of the 

 planets, which are also given by Diodorus, are the only ones 

 used by Plato and Aristotle; whereas later, for example 

 in the book " de Mundo," falsely ascribed to Aristotle, we 

 find both kinds of appellations the mythological and the 



