The answer to this is easy. I believe in all the astronomy that was believed by Thales. I do not question the statements relative to the heavenly bodies that were delivered by the wise men of the East. But the supposed discoveries that were made in the eighteenth, and even in the latter part of the seventeenth century, purporting to ascertain the precise distance of the sun, the planets, and even of the fixed stars, are matters entirely distinct from this.
Among the earliest astronomers of Greece were Thales, Anaximander, Anaximenes and Anaxagoras. Thales, we are told, held that the earth is a sphere or globe, Anaximenes that it is like a round, flat table; Anaximander that the sun is like a chariot-wheel, and is twenty-eight times larger than the earth. Anaxagoras was put in prison for affirming that the sun was by many degrees larger than the whole Peloponnesus(66). Kepler is of opinion that all the stars are at an equal distance from us, and are fixed in the same surface or sphere.
(66) Plutarch, De Placitis Philosophorum. Diogenes Laertius.
In reality the observations and the facts of astronomy do not depend either upon the magnitudes or the distances of the heavenly bodies. They proceed in the first place upon what may lie seen with the naked eye. They require an accurate and persevering attention. They may be assisted by telescopes. But they relate only to the sun and the planets. We are bound to ascertain, as nearly as possible, the orbits described by the different bodies in the solar system: but this has still nothing to do, strictly speaking, with their magnitudes or distances. It is required that we should know them in their relations to each other; but it is no preliminary of just, of practical, it might almost be said, of liberal science, that we should know any thing of them absolutely.
The unlimited ambition of the nature of man has discovered itself in nothing more than this, the amazing superstructure which the votaries of contemplation within the last two hundred years have built upon the simple astronomy of the ancients. Having begun to compute the distances of miles by millions, it appears clearly that nothing can arrest the more than eagle-flight of the human mind. The distance of the nearest fixed star from the earth, we are informed, is at least 7,000,000,000,000 miles, and of another which the astronomers name, not less than 38 millions of millions of miles. The particles of light are said to travel 193,940 miles in every second, which is above a million times swifter than the progress of a cannon-ball(67). And Herschel has concluded, that the light issuing from the faintest nebulae he has discovered, must have been at this rate two millions of years in reaching the Barth(68).
(67) Ferguson, Section 216. "Light moves," says Brewster, Optics, p. 2,
"from one pole of the earth to the other in the 24th part of a second: a
velocity which surpasses all comprehension."
(68) Brinkley, Astronomy, p. 130.
SECTION III.
The next process of the modern astronomer is to affirm the innumerable orbs around us, discovered with the naked eye, or with which we are made acquainted by the aid of telescopes, to be all stocked with rational inhabitants. The argument for this is, that an all-wise and omnipotent creator could never have produced such immense bodies, dispersed through infinite space, for any meaner purpose, than that of peopling them with "intelligent beings, formed for endless progression in perfection and felicity(69)."