The Essayist’s suggested analogy between man’s relation to time and to space appears to us not understood, in either its scope or nature, by Sir David Brewster. At this we are as much surprised, as at the roughness with which he characterises the argument, as “the most ingenious though shallow piece of sophistry he has ever encountered in modern dialectics.” The Essayist suggests a comparison between the numbers expressing the four magnitudes and distances,—of the earth, the solar system, the fixed stars, and the nebulæ—and the numbers expressing the antiquity of the four geological periods “for the sake of giving definiteness to our notions.” Sir David abstains from quoting these last expressions, and alleges that the Essayist, “quitting the ground of analogy,” founds an elaborate argument on the mutual relation of an atom of time and an atom of space. The “argument” Sir David thus presents to his readers, the capital and italic letters being his own: “That is, the earth, the ATOM OF SPACE, is the only one of the planetary and sidereal worlds that is inhabited, because it was so long without inhabitants, and has been occupied only an ATOM OF TIME.”[[65]] “If any of our readers,” he adds, “see the force of this argument, they must possess an acuteness of perception to which we lay no claim. To us, it is not only illogical; it is a mere sound in the ear, without any sense in the brain.” This is the language possibly befitting an irritated Professor towards an ignorant and conceited student, but hardly suitable when Sir David Brewster is speaking of such an antagonist as he cannot but know he has to deal with. It does not appear to us the Essayist’s attempt, or purpose, to establish any arbitrary absolute relation between time and space, or definite proportions of either, as concurring or alternative elements for determining the probability of a plurality of worlds. But he says to the dogmatic astronomical objector to Christianity, Such arguments as you have hitherto derived from your consideration of SPACE, MULTITUDE, and MAGNITUDE, for the purpose of depressing man into a being beneath his Maker’s special notice, I encounter by arguments derived from recent disclosures concerning another condition of existence—DURATION, or TIME. Protesting that neither Time nor Space has any true connection with the subject, nevertheless I will turn your own weapons against yourself. My argument from Time shall at least neutralise yours from Space: mine shall involve the conditions of yours, fraught with their supposed irresistible force, and falsify them in fact, as forming premises whence may be deduced derogatory inferences concerning man. The Essayist’s ingenious and suggestive argument is intended not to prove an opinion, but to remove an objection; which, according to the profound thinker, Bishop Butler, is the proper office of analogy. It is asked, for instance, how can you suppose that man, such as he is represented to be, occupies only an immeasurably minute fraction of existing matter? and it is answered, I find that man occupies only an immeasurably minute fraction of elapsed time: and this is, to me, an answer to the “How,” as concluding improbability. How is balanced against How: Difficulty against difficulty: they neutralise each other, and leave the great question, the great reality, standing as it did before either was suggested, to be dealt with according to such evidence as God has vouchsafed us. We, therefore, do not see that the Essayist is driven to say, as Sir David Brewster alleges he is, either that because man has occupied only an atom of space, he must live only an atom of time on the earth;[[66]] or that because he has lived only an atom of time, he must occupy but an atom of space. In dismissing this leading portion of the Essayist’s reasonings, we shall say only that we consider it worthy of the attention of all persons occupied in speculations of this nature, as calculated to suggest trains of novel, profitable, and deeply interesting reflection.
Thus far the Essayist, as followed by his opponent, on the assumption that the other bodies of the universe are fitted, equally with the earth, to be the abodes of life. But are they? Here we are brought to the last stage of the Essayist’s speculations—What physical EVIDENCE have we that the other bodies of the Solar System, besides the Earth, the Fixed Stars, and the Nebulæ, are structures capable of supporting human life, of being inhabited by Rational and Moral Beings?
The great question, in its physical aspect, is now fully before us: Is there that analogy on which the pluralist relies?
For the existence of Life several conditions must concur; and any of these failing, life, so far as we know anything about it, is impossible. Not air, only, and moisture, but a certain temperature, neither too hot nor too cold, and a certain consistence, on which the living frame can rest. Without the other conditions, an atmosphere alone does not make life possible; still less, prove its existence. A globe of red-hot metal, or of solid ice, however well provided with an atmosphere, could not be inhabited, so far as we can conceive. The old maxim of the logicians is true: that it requires all the conditions to establish the affirmative, but that the negative of any one proves the negative.
First, as to the smallest tenants of our system, the thirty[[67]] planetoids, some of which are certainly no larger than Mont Blanc.
Sir David Brewster dare not venture to suggest that they are inhabited, or in any condition to become so, any more than meteoric stones, which modern science regards as masses of matter, moving, like the planets, in the celestial spaces, subject to the gravitating attraction of the Sun; the Earth encountering them occasionally, either striking directly upon them, or approaching to them so closely that they are drawn by the terrestrial attraction, first within the atmosphere, and afterwards to the earth’s surface.[[68]] Here our Essayist gives a thrust at his Pluralist opponent not to be parried, asking him why he shrunk from asserting the planetoids and meteoric stones to be inhabited? If it be because of their being found to be uninhabited, or of their smallness, then “the argument that they are inhabited because they are planets fails him.”[[69]]
“There is, then,” says elsewhere the wary Essayist,[[70]] “a degree of smallness which makes you reject the supposition of inhabitants. But where does that degree of smallness begin? The surface of Mars is only one-fourth that of the Earth. Moreover, if you allow all the planetoids to be uninhabited, those planets which you acknowledge to be probably uninhabited far outnumber those with regard to which even the most resolute Pluralist holds to be inhabited. The majority swells every year; the planetoids are now thirty. The fact of a planet being inhabited, then, is, at any rate, rather the exception than the rule; and therefore must be proved, in each case, by special evidence. Of such evidence I know not a trace!”
We may add, also, that Dr Lardner, vouched by Sir David Brewster, as we shall soon see, to be a thoroughly competent witness, gives up the planetoids as seats of habitation for animal life.[[71]]
Let us now, would say our Essayist, proceed on our negative tour, so to speak, and hasten to pay our respects to the Moon, our nearest neighbour, and whose distance from the Sun is admitted to adapt her, so far, for habitation.[[72]] If it appear, by strong evidence, that the Moon is not inhabited, then there is an end of the general principle, that all the bodies of the solar system are inhabited, and that we must begin our speculation about each with this assumption. If the Moon be not inhabited, then, it would seem, the belief that each special body in the system is inhabited, must depend upon reasons specially belonging to that body, and cannot be taken for granted without these reasons.[[73]] Now, as to the Moon, we have latterly acquired the means of making such exact and minute inquiries, that at the meeting of the British Association at Hull last year, Mr Phillips, an eminent geologist, stated that astronomers can discern the shape of a spot on the Moon’s surface, only a few hundred feet in breadth. Passing by, however, the Essayist’s brief but able account of the physical condition of this satellite of ours, we will cite the recent testimony of one accredited by Sir David Brewster[[74]] as “a mathematician and a natural philosopher, who has studied, more than any preceding writer, the analogies between the Earth and the other planets”—Dr Lardner, who, in the third volume (published since our last Number appeared) of the work placed at the head of this article, thus concludes his elaborate account of the Moon, as now regarded by the most enlightened astronomers—after proving it to be “as exempt from an atmosphere as is the utterly exhausted receiver of a good air-pump!”
“In fine, the entire geographical character of the moon, thus ascertained by long-continued and exact telescopic surveys, leads to the conclusion, that no analogy exists between it and the earth which could confer any probability on the conjecture that it fulfils the same purposes in the economy of the universe; and we must infer, that whatever be its uses in the solar system, or in the general purposes of creation, it is not a world inhabited by organised races such as those to which the earth is appropriated.”[[75]]