Worlds, Plurality of
Worlds, Plurality Of The question whether other globes besides the earth are inhabited is one of great interest both to the student of nature and to the theologian. There re e two classes of arguments that may be brought to bear upon its solution.
1. Probabilities from Analogy. — From the fact that our own globe is populated, it has naturally been inferred that the stellar bodies are so likewise. Else why do they exist? Surely, it is contended, they cannot have been formed merely for the delectation of the comparatively few denizens of this relatively insignificant orb. But are we sure of that? If man be the only intelligent creature, it is inconsistent neither with reason nor with Scripture to suppose that the whole visible creation was intended for his express benefit and behoof. Moreover, the presumption from analogy almost wholly breaks down if extended to its legitimate results in this question. If the other celestial spheres are inhabited, it is doubtless with rational and moral beings like ourselves, for mere unaccountable animals would be a sorry outcome of so vast creative power and skill. In that case they are free of will, and some of them, at least, have probably fallen, like men and angels. Has a Redeemer been provided for them also? It would seem not, from the silence of revelation on the subject, or rather from the implications of soteriology. It is hazardous to aver that Christ has died. for other worlds than our own, or that he will ever do so. Here is apparently an incongruity which clogs the hypothesis of other planetary bodies being inhabited.
2. Evidence of Science. — This is really a problem within the domain of physics, and should be decided by an appeal to known facts. These are neither few nor indistinct. The moon, which is our nearest and most familiar neighbor, is pronounced by the latest observers to be utterly uninhabitable. She has neither atmosphere nor water, at least not on the hemisphere which is constantly presented towards us. But she has enormously deep craters, which speak of fearful convulsions upon her surface, and her face appears to be entirely destitute of all possibilities even of vegetation. In fact, an ordinary-sized farm, or even a considerable dwelling, had it existed there, would probably have been detected by the powerful telescopes which have scanned and even photographed the lunar landscape.
Turning now to Venus, our nearest fellow-planet, we find her not much more favorably situated. She has so wide a variation of temperature at different seasons of the year, owing to the great obliquity of her ecliptic, as must be fatal to all animal or vegetable existence. Mercury, the sole other planet within our orbit, is even worse off, being so near the sun that no life could possibly endure the terrific heat. Mars, our first outside neighbor, is circumstanced most like ourselves; but the close observation, for which he affords peculiar facilities, have failed to discover any positive indications of habitability. Of the remaining members of our own planetary system, Jupiter and Saturn may perhaps have a temperature capable of supporting life, but the different colored moons of the former and the singular electric zone of the latter, besides their exceedingly low density, imply a difference of constitution incompatible with the conditions known upon our own globe. The improbability of their being inhabited is increased by the revelations of the spectrum, which discloses a composition of each materially different from the other and from the earth's. As for the asteroids, which occupy the place of a lost intermediate sphere, they seem to have consisted of terribly explosive materials, fragments of which frequently fall to us in the form of meteorolites, and furnish compounds not found in terrestrial bodies. The more distant planets are too intensely cold to admit of life in any form.
The only remaining member of our planetary family is the central orb, the sun itself. If its body is coequal with its luminous disk, the surface must be too rare to sustain beings of anything more than ethereal weight; and whether this be the real body of the sun, or whether the interior sphere, glimpses of which are obtained through the so-called "spots," and which only appear dark by contrast with the vivid incandescence of the atmosphere, still the fiery ardor of the surface must be such as to preclude all life of which we can form any conception.
The fixed stars are but the central suns of other systems. and are evidently of a like nature with our own. Their planets, if they have any, are a matter of pure conjecture. Comets and nebulae are too flimsy in their structure to form a habitable abode for creatures of any sort; they seem, indeed, to be but fire-mist or electric vapor. We have thus exhausted the range of space, and find no home except earth at all suitable or possible for a creature having the least resemblance to man. To suppose a being capable of existing under the abnormal and intolerable conditions of vitality such as we have ascertained is as gratuitous as it is preposterous. We cannot, it is true, limit the power and resources of the Almighty, but we are forced by the facts in the case, and by the invariable analogies of all life with which we are acquainted, to deny its existence upon the other celestial bodies. Nor is there the slightest evidence that any of the globes except our own has ever been inhabited. or is likely to be so in the future. See Proctor, Other Worlds than Ours (Lond. 1870).