~ 19 ~
This order, which, if we leave the Moon out of consideration, and put the Earth in the place of the Sun, is a correct order for the distance of the planets from the Sun and was based by the astronomers on their calculation of the time taken by each planet in its revolution, was the accepted order possibly from the days of Pythagoras and certainly from the second century B.C.[1] through the imperial period, the Dark Ages and the Middle Ages down to the establishment of Copernican astronomy. Thus, to take two examples from earlier and later times, we find it in Cicero's treatise on Divination in which he includes astrology[2]. And it forms the framework of Dante's Paradiso. Dante, as every reader will remember, ascends through seven zones beginning with the Moon and ending with Saturn, whence he passes into the eighth and ninth heavens known as the Primum Mobile and Empyrean which later astrology had added to the Seven.
On the other hand, the order of the planets in the week, as clearly reflected in the existing names, is:
Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn.
A full discussion of this difference between the
- ↑ V. infra, p. 58
- ↑ Cic. De Divinatione, II, 91. In another treatise, the De Natura Deorum, II, 53, he makes Venus and Mercury change places.
