Dismiss the fixed stars and the other planets and consider the demonstrations of Aristarchus in his treatise,
On Sizes and Distances, that
the distance of the sun is more than 18 times and less than 20 times the distance of the moon,
that is its distance from us.
This is Proposition 7 of Aristarchus’s treatise, the full title of which is On the Sizes and Distances of the Sun and Moon. The treatise is edited and translated by Sir Thomas Heath in his Aristarchus of Samos, pp. 352 ff. According to the highest estimate, however, the moon’s distance from us is said to be 56 times the radius of the earth.
This was not the highest estimate hitherto given, nor have I been able to identify its author. cf. on this matter and the subsequent calculations in this passage Class. Phil. xlvi (1951), pp. 140-141. No attempt is made to give equivalents for stades in calculations, for it is uncertain what stade is meant in any one place. Schiaparelli assumes everywhere the Olympic stade of 185 metres (Scritti sulla storia della astronomia antica, i, p. 333, n. 3 and p. 342, n. 1); Heath argues that Eratosthenes used a stade of 157.5 metres and Ptolemy the royal stade of 210 metres (Aristarchus of Samos, pp. 339 and 346); and Raingeard (p. 83 on 925 D 6) assumes without argument that Plutarch used the Attic stade of 177.6 metres. Even according to the mean calculations this radius is 40,000 stades; and, if we reckon from this, the sun is more than 40,300,000 stades distant from the moon. She has migrated so far from the sun on account of her weight and has moved so close to the earth that, if properties
There is a play on the meaning of τὰs οὐσίας, substances,
as property
or estates
and as the real nature of things.
are to be determined by locations, the lot, I mean the position, of earth lays an action against the moon and she is legally assignable by right of propinquity and kinship to the chattels real and personal of earth. We do not err at all, I think, if granting such altitude and extension to the things called
upper
we leave what is
down below
also
some room to move about in and so much latitude as there is from earth to moon. For as he is immoderate who calls only the outermost surface of the heaven
up
and all else
down,
so is he intolerable who restricts
down
to the earth or rather to the centre; but both there and here some extension must be granted since the magnitude of the universe permits it. The claim that everything away from the earth is
ipso facto up
and
on high
answered by a counter-claim that what is away from the circuit of the fixed stars is
ipso facto down.