[90] The philosophers of antiquity were divided in their opinions respecting the great question, whether the active properties of material bodies, which produce the phænomena of nature, are inherent in them, and necessarily attached to them, or whether they are bestowed upon them by some superior power or being. The Academics and Peripatetics generally adopted the latter opinion, the Stoics the former: Pliny adopts the doctrine of the Stoics; see Enfield’s Hist. of Phil. i. 229, 283, 331.
[91] I may remark, that the astronomy of our author is, for the most part, derived from Aristotle; the few points in which they differ will be stated in the appropriate places.
[92] This doctrine was maintained by Plato in his Timæus, p. 310, and adopted by Aristotle, De Cœlo, lib. ii. cap. 14, and by Cicero, De Nat. Deor. ii. 47. The spherical form of the world, οὐρανὸς, and its circular motion are insisted upon by Ptolemy, in the commencement of his astronomical treatise Μεγάλη Σύνταξις, Magna Constructio, frequently referred to by its Arabic title Almagestum, cap. 2. He is supposed to have made his observations at Alexandria, between the years 125 and 140 A.D. His great astronomical work was translated into Arabic in the year 827; the original Greek text was first printed in 1538 by Grynæus, with a commentary by Theon. George of Trebisond published a Latin version of it in 1541, and a second was published by Camerarius in 1551, along with Ptolemy’s other works. John Muller, usually called Regiomontanus, and Purback published an abridgement of the Almagest in 1541. For an account of Ptolemy I may refer to the article in the Biog. Univ. xxxv. 263 et seq., by Delambre, also to Hutton’s Math. Dict., in loco, and to the high character of him by Whewell, Hist. of the Inductive Sciences, p. 214.
[93] See Ptolemy, ubi supra.
[94] This opinion, which was maintained by Pythagoras, is noticed and derided by Aristotle, De Cœlo, lib. ii. cap. 9. p. 462-3. A brief account of Pythagoras’s doctrine on this subject is contained in Enfield’s Philosophy, i. 386.
[95] Pliny probably here refers to the opinion which Cicero puts into the mouth of one of the interlocutors in his treatise De Nat. Deor. ii. 47, “Quid enim pulchrius ea figura, quæ sola omnes alias figuras complexa continet, quæque nihil asperitatis habere, nihil offensionis potest, nihil incisum angulis, nihil anfractibus, nihil eminens, nihil lacunosum?”
[96] The letter Δ, in the constellation of the triangle; it is named Δελτωτὸν by Aratus, l. 235; also by Manilius, i. 360. We may remark, that, except in this one case, the constellations have no visible resemblance to the objects of which they bear the name.
[97] “Locum hunc Plinii de Galaxia, sive Lactea via, interpretantur omnes docti.” Alexandre, in Lemaire, i. 227. It may be remarked, that the word vertex is here used in the sense of the astronomical term zenith, not to signify the pole.
[98] De Ling. Lat. lib. iv. p. 7, 8. See also the remarks on the derivation of the word in Gesner, Thes., in loco.
[99] “Signifer.” The English term is taken from the Greek word Ζωδιακὸς, derived from Ζῶον; see Aristotle, De Mundo, cap. 2. p. 602. The word Zodiacus does not occur in Pliny, nor is it employed by Ptolemy; he names it λοξὸς κύκλος, obliquus circulus; Magn. Const. i. 7, 13, et alibi. It is used by Cicero, but professedly as a Greek term; Divin. ii. 89, and Arati Phænom. l. 317. It occurs in Hyginus, p. 57 et alibi, and in A. Gellius, 13. 9. Neither signifer taken substantively, nor zodiacus occur in Lucretius or in Manilius.