De Facie Quae in orbe Lunae Apparet

Apollonides broke in and inquired what the opinion of Clearchus was. You are the last person, I said, who has any right not to know a theory of which geometry is, as it were, the very hearth and

home. The man, you see, asserts that what is called the face consists of mirrored likenesses, that is images of the great ocean reflected in the moon,[*](Similar theories are referred to by Aëtius, ii. 30. 1 (Dox. Graeci, p. 361 B 10-13) = Stobaeus, Eclogae, i. 26. 4; Lucian, Icaromenippus, § 20; Simplicius, Caelo, p. 457. 15-16. Such a theory is recorded and refuted by Ibn Al-Haitham, the Arabic astronomer of the tenth and eleventh centuries (cf, Schoy’s translation, pp. 1-2 and 5-6). Emperor Rudolph II believed the spots on the moon to be the reflection of Italy and the large Italian islands (cf. Kepler, Opera Omnia, ii, p. 491 cited by Pixis, Kepler als Geography p. 102); and A. von Humboldt (Kosmos, iii, p. 544 [Stuttgart, 1850]) tells of a Persian from Ispahan who assured him that what we see in the moon is the map of our earth (cf. Ebner, Geographische Hinweise und Anklänge in Plutarchs Schrift, de facie, p. 13, n. 3).) for the visual ray when reflected naturally reaches from many points objects which are not directly visible and the full moon is itself in uniformity and lustre[*](i.e. in the evenness and polish of its surface.) the finest and clearest of all mirrors. Just as you think, then, that the reflection of the visual ray to the sun accounts for the appearance of the (rainbow) in a cloud where the moisture has become somewhat smooth and (condensed),[*](For the rainbow as a reflection of the sun in the cloud cf. Iside, 358 F, Amatorius, 765 E - F (where there is a strong verbal similarity to the present passage), Placitis, 894 C - F (= Aëtius, iii. 5, 3-10 and 11 [Dox. Graeci, pp. 372-373]). According to Aëtius, iii. 5. 11 ( = Placitis, 894 F) the theory was held by Anaxagoras (cf. frag. B 19 = ii, p. 41. 8-11 [Diels-Kranz]). It is developed by Aristotle in Meteorology, iii. 4, 373 A 32 375 B 15 (cf. Areius Didymus’s Epitome, frag. 14 = Dox. Graeci, p. 455.14 ff., and Seneca, Nat. Quaest. i. 3). Diogenes Laertius, vii. 152 cites Posidonius for the definition ἶριν δ’ εἶναι ὡς Ποσειδώνιός φησιν ἔμφασιν ἡλίου τμήματος ἣ ἐν νέφει δεδροσιμένῳ, κοίλῳ καὶ συνεχεῖ πρὸς φαντασίαν, ὡς ἐν κατόpτρῳ φανταζομένην κατὰ κύκλου περιφέρειαν (cf. Seneca, Nat. Quaest. i. 5. 13); and Adler (Diss. Phil. Vind. x, pp. 128-129) contends that Posidonius was Plutarch’s source for the formulation of the theory. Plutarch’s oἴεσθ’ ὑμεῖς, however, addressed to Apollonides must be intended to ascribe the theory generally to you mathematicians; and this is confirmed by the passage of Iside cited above, which reads: καἰ καθάπερ οἱ μαθηματικοὶ τὴν ἶριν λέγουσι On the difference between the theories of Aristotle and Posidonius cf. O. Gilbert, Die meteorologischen Theorien des griechischen Altertums, pp. 614-616.) so Clearchus thought that the outer ocean is seen in the moon, not in the place where it is but in the place whence the visual ray has been deflected to the ocean and the reflection of the ocean to us. So Agesianax again has somewhere said:

1. Or swell of ocean surging opposite
2. Be mirrored in a looking-glass of flame.

[*](Powell (Collectanea Alexandrina, p. 9) prints these lines as fragment 2 of the Phaenomena of Hegesianax; see note a on p. 39 supra.)