Astronomica

Philosophy, from whom he had been taught the principles of LogicThe formal study of reasoning and argument.. For this reason, the non-Greeks taught the Greeks the history of eclipses. The Greeks investigated the causes of these failures of light, and at last, though late, they discovered them. First among them was Conon of Samos, who collected the solar eclipses observed by the Egyptians; then Hipparchus—a man who was, as Pliny says, a counselor to nature—paved the way for them. Hipparchus was the first to adapt the eclipses of both celestial bodies, as recorded by the ChaldeansA term often used for the astronomers and astrologers of Babylon., to the months of all the Greek nations. From this divine work, Ptolemy drew the entire history of lunar eclipses, who in his own great work attributes many things received from the ancients, to none more than Hipparchus.

But if we consider the matter more closely, even before any Chaldean observation of eclipses had reached the Greeks, Thales of Miletus had already learned of the eclipses of both luminaries without any non-Greek teacher, and had made such progress in them that he predicted the eclipses themselves long in advance. And certainly, while we admit that the Greeks reached Astronomy late, we nevertheless firmly assert that the Chaldeans possessed only a original: "ὁλοσχερῆ" (holoscherē) general knowledge, not an original: "ἀκριβῆ" (akribē) exact or precise one. Since they divided the field into two parts—the original: "τὸ μετεωρολογικὸν" (to meteōrologikon) meteorological part, which deals with motions, and the original: "τὸ ἀποτελεσματικὸν" (to apotelesmatikon) prognostic part, which promises the divination of future events—we show that the Greeks learned almost nothing from the Chaldeans in the former. Of the latter part, however, which incurs censure in many ways—from good morals, from Philosophy, and from Geometry itself—the Chaldeans were the authors