Let us pass to astronomy. This was one of the sciences which Plato exhorted his disciples to learn, but for reasons far removed from common habits of thinking. Shall we set down astronomy, says Socrates, among the subjects of study? [Platos Republic, Book VII.] I think so, answers his young friend Glaucon: to know something about the seasons, the months, and the years is of use for military purposes, as well as for agriculture and navigation. It amuses me, says Socrates, to see how afraid you are lest the common herd of men should accuse you of recommending useless studies. He then proceeds, in that pure and magnificent diction which, as Cicero said, Jupiter would use if Jupiter spoke Greek, to explain that the use of astronomy is not to add to the vulgar comforts of life, but to assist in raising the mind to the contemplation of things which are to be perceived by the pure intellect alone. The knowledge of the actual motions of the heavenly bodies Socrates considers as of little value. The appearances which make the sky beautiful at night are, he tells us, like the figures which a geometrician draws on the sand, mere examples, mere helps to feeble minds. We must get beyond them; we must neglect them; we must attain to an astronomy which is as independent of the actual stars as geometrical truth is independent of the lines of an ill-drawn diagram. This is, we imagine, very nearly, if not exactly, the astronomy which Bacon compared to the ox of Prometheus [De Augmentis, Lib. 3, cap. 4], a sleek, well-shaped hide, stuffed with rubbish, goodly to look at, but containing nothing to eat. He complained that astronomy had, to its great injury, been separated from natural philosophy, of which it was one of the noblest provinces, and annexed to the domain of mathematics. The world stood in need, he said, of a very different astronomy, of a living astronomy [Astronomia viva], of an astronomy which should set forth the nature, the motion, and the influences of the heavenly bodies, as they really are. [Que substantiam et motum et influxum clestium, prout re vera sunt, proponat.]
Lord Thomas Babington Macaulay: Lord Bacon, July, 1837.
Against filling the heavens with fluid mediums, unless they be exceeding rare, a great objection arises from the regular and very lasting motions of the planets and comets in all manner of courses through the heavens.