Note 29 — CONTENTS. (continued 3)
Reading edition
Similar reasoning applies to the moons of Jupiter, and it so chances that the result in their case comes out exactly the same as in the case of Saturn; all the Jovian moons, if full together, would reflect only the sixteenth part of the light which we receive from the full moon. It is strange that scientific men of considerable mathematical power have used the argument from design apparently supplied by the satellites, without being at the pains to test its validity by the simple mathematical calculations necessary to determine the quantity of light which these bodies can reflect to the planets round which they travel. Brewster and Whewell, though they took opposite sides in the controversy about other inhabited worlds, agreed in this. Brewster, of course, holding the theory that all the planets are inhabited, very naturally accepted the argument from design in this case. Whewell, in opposing that theory, did not dwell at all upon the subjects of the satellites. But in his 'Bridgewater Treatise on Astronomy and General Physics,' he says, 'Taking only the ascertained cases of Venus, the Earth, Jupiter, and Saturn, we conceive that a person of common understanding will be strongly impressed with the persuasion that the satellites are placed in the system with a view to compensate for the diminished light of the sun at greater distances. Mars is an exception; some persons might conjecture from this case that the arrangement itself, like other useful arrangements, has been brought about by some wider law which we have not yet detected. But whether or not we entertain such a guess (it can be nothing more), we see in other parts of creation so many examples of apparent exceptions to rules, which are afterwards found to be capable of explanation, or to be provided for by particular contrivances, that no one familiar with such contemplations will, by one anomaly, be driven from the persuasion that the end which the arrangements of the satellites seem suited to answer is really one of the ends of their creation.'