From Burnet's Introduction

XIII. The Scientific Chracter of the Early Greek Cosmology
It is necessary to insist on the scientific character of the philosophy we are about to study. We have seen that the Eastern peoples were considerably richer than the Greeks in accumulated facts, though these facts had not been observed for any scientific purpose, and never suggested a revision of the primitive view of the world. The Greeks, however, saw in them something that could be turned to account, and they were never as a people slow to act on the maxim, Chacun prend son bien partout où il le trouve. The visit of Solon to Croesus which Herodotos describes, however unhistorical it may be, gives us a good idea of this spirit. Croesus tells Solon that he has heard much of "his wisdom and his wanderings," and how, from love of knowledge (φιλοσοφέων), he has travelled over much land for the purpose of seeing what was to be seen (θεωρίης εἵνεκεν). The words θεωρίη, φιλοσοφίη, and ἱστορίη, are, in fact, the catchwords of the time, though they had, no doubt, a somewhat different meaning from that they were afterwards made to bear at Athens.⁶¹ The idea that underlies them all may, perhaps, be rendered in English by the word Curiosity; and it was just this great gift of curiosity, and the desire to see all the wonderful things--pyramids, inundations, and so forth--that were to be seen, which enabled the Ionians to pick up and turn to their own use such scraps of knowledge as they could come by among the barbarians. No sooner did an Ionian philosopher learn half-a-dozen geometrical propositions, and hear that the phenomena of the heavens recur in cycles, than he set to work to look for law everywhere in nature, and, with an audacity almost amounting to ὕβρις, to construct a system of the universe. We may smile at the medley of childish fancy and scientific insight which these efforts display, and sometimes we feel disposed to sympathise with the sages of the day who warned their more daring contemporaries "to think the thoughts befitting man's estate" (ἀνθρώπινα φρονεῖν). But we shall do well to remember that even now it is just such hardy anticipations of experience that make scientific progress possible, and that nearly every one of these early inquirers made some permanent addition to positive knowledge, besides opening up new views of the world in every direction.

There is no justification either for the idea that Greek science was built up by more or less lucky guesswork, instead of by observation and experiment. The nature of our tradition, which mostly consists of Placita--that is; of what we call "results"--tends, no doubt, to create this impression. We are seldom told why any early philosopher held the views he did, and the appearance of a string of "opinions" suggests dogmatism. There are, however, certain exceptions to the general character of the tradition; and we may reasonably suppose that, if the later Greeks had been interested in the matter, there would have been many more. We shall see that Anaximander made some remarkable discoveries in marine biology, which the researches of the nineteenth century have confirmed (§ 22), and even Xenophanes supported one of his theories by referring to the fossils and petrifactions of such widely separated places as Malta, Paros, and Syracuse (§ 59). This is enough to show that the theory, so commonly held by the earlier philosophers, that the earth had been originally in a moist state, was not purely mythological in origin, but based on biological and palaeontological observations. It would surely be absurd to imagine that the men who could make these observations had not the curiosity or the ability to make many others of which the memory is lost. Indeed, the idea that the Greeks were not observers is ludicrously wrong, as is proved by the anatomical accuracy of their sculpture, which bears witness to trained habits of observation, while the Hippokratean corpus contains models of scientific observation at its best. We know, then, that the Greeks could observe well, and we know that they were curious about the world. Is it conceivable that they did not use their powers of observation to gratify that curiosity? It is true that they had not our instruments of precision; but a great deal can be discovered by the help of very simple apparatus. It is not to be supposed that Anaximander erected his gnomon merely that the Spartans might know the seasons.⁶²

Nor is it true that the Greeks made no use of experiment. The rise of the experimental method dates from the time when the medical schools began to influence the development of philosophy, and accordingly we find that the first recorded experiment of a modern type is that of Empedokles with the klepsydra. We have his own account of this (fr. 100), and we can see how it brought him to the verge of anticipating Harvey and Torricelli. It is inconceivable that an inquisitive people should have applied the experimental method in a single case without extending it to other problems.

Of course the great difficulty for us is the geocentric hypothesis from which science inevitably started, though only to outgrow it in a surprisingly short time. So long as the earth is supposed to be in the centre of the world, meteorology, in the later sense of the word, is necessarily identified with astronomy. It is difficult for us to feel at home in this point of view, and indeed we have no suitable word to express what the Greeks at first called an οὐρανός. It will be convenient to use the term "world" for it; but then we must remember that it does not refer solely, or even chiefly, to the earth, though it includes that along with the heavenly bodies.

The science of the sixth century was mainly concerned, therefore, with those parts of the world that are "aloft" (τὰ μετέωρα) and these include such things as clouds, rainbows, and lightning, as well as the heavenly bodies.⁶³ That is how the latter came sometimes to be explained as ignited clouds, an idea which seems astonishing to us.⁶⁴ But even that is better than to regard the sun, moon, and stars as having a different nature from the earth, and science inevitably and rightly began with the most obvious hypothesis, and it was only the thorough working out of this that could show its inadequacy. It is just because the Greeks were the first people to take the geocentric hypothesis seriously that they were able to go beyond it. Of course the pioneers of Greek thought had no clear idea of the nature of scientific hypothesis, and supposed themselves to be dealing with ultimate reality, but a sure instinct guided them to the right method, and we can see how it was the effort to "save appearances"⁶⁵ that really operated from the first. It is to those men we owe the conception of an exact science which should ultimately take in the whole world as its object. They fancied they could work out this science at once. We sometimes make the same mistake nowadays, and forget that all scientific progress consists in the advance from a less to a more adequate hypothesis. The Greeks were the first to follow this method, and that is their title to be regarded as the originators of science.

61. Still, the word θεωρία never lost its early associations, and the Greeks always felt that the θεωρητικὸς βίος meant literally "the life of the spectator." Its special use and the whole theory of the "three lives" seem to be Pythagorean. (See § 45.)

62. As we saw, the word γνώμων properly means a carpenter's square (p. 21, n. 1), and we learn from Proclus (in Eucl. I. p. 283, 7) that Oinopides of Chios used it in the sense of a perpendicular (κάθετος) The instrument so called was simply an upright erected on a flat surface, and its chief use was to indicate the solstices and the equinoxes by means of its shadow. It was not a sundial; for it afforded no means of dividing the day into equal hours, though the time of day would be approximately inferred from the length of the shadow cast by it. For the geometrical use of the term, see below, p. 103, n. 1.

63. The restricted sense of μετεωρολογία only arose when Aristotle introduced for the first time the fateful distinction between the οὐρανός and the "sublunary" region, to which it was now confined. In so far as they make no such distinction, the early cosmologists were more scientific than Aristotle. Their views admitted of correction and development; Aristotle's theory arrested the growth of science.

64. It is well, however, to remember that Galileo himself regarded comets as meteorological phenomena.

65. This phrase originated in the school of Plato. The method of research in use there was for the leader to "propound" (προτείνειν, προβάλλεσθαι) it as a "problem" (πρόβλημα) to find the simplest "hypothesis" (τίνων ὑποτεθέντων) on which it is possible to account for and do justice to all the observed facts (σῴζειν τὰ φαινόμενα). Cf. Milton, Paradise Lost, viii. 81, "how build, unbuild, contrive | To save appearances."