Again, a certain practical knowledge of astronomy, a certain skill in the study of the stars, he strongly insisted on. Every one should know enough of the science to be able to discover the hour of the night or the season of the month or year, for the purposes of travel by land or sea--the march, the voyage, and the regulations of the watch; (11) and in general, with regard to all matters connected with the night season, or with the month, or the year, (12) it was well to have such reliable data to go upon as would serve to distinguish the various times and seasons. But these, again, were pieces of knowledge easily learnt from night sportsmen, (13) pilots of vessels, and many others who make it their business to know such things. As to pushing the study of astronomy so far as to include a knowledge of the movements of bodies outside our own orbit, whether planets or stars of eccentric movement, (14) or wearing oneself out endeavouring to discover their distances from the earth, their periods, and their causes, (15) all this he strongly discountenanced; for he saw (he said) no advantage in these any more than in the former studies. And yet he was not unversed (16) in the subtleties of astronomy any more than in those of geometry; only these, again, he insisted, were sufficient to wear out a man's lifetime, and to keep him away from many more useful pursuits. (11) Schneid. cf. Plat. "Rep." vii. 527 D. (12) "Occurrences connected with the night, the month, or year." e.g. the festival of the Karneia, the {tekmerion} (point de repere) of which is the full moon of August. Cf. Eur. "Alc." 449. (13) See Plat. "Soph." 220 D; above, III. xi. 8; "Cyrop." I. vi. 40; "Hunting," xii. 6; Hippocr. "Aer." 28. (14) See Lewis, "Astron. of the Ancients"; cf. Diog. Laert. vii. 1. 144. (15) Or, "the causes of these." (16) {oude touton ge anekoos en}. He had "heard," it is said, Archelaus, a pupil of Anaxagoras. Cf. Cic. "Tusc." V. iv. 10.