Imagens das páginas

quelque autre philosophe peut expliquer ces phénomènes par les loix du mécanisme, bien loin d'etre contredit tous les savans l'en remercieront *."

Aggregation of Matter.

[ocr errors]

TO TAKE another example of those phenomena of the universe, which have not been reduced to mechanical causes, we may cite that which is dwelt upon by Newton in the following passage: "If the matter of the sun and planets was evenly disposed throughout an infinite space, it would never convene into one mass; but some of it would convene into one mass, and some into another, so as to make an infinite number of masses, scattered at great distances from one to another throughout all the infinite space. And thus might the sun and the fixed stars be formed, supposing the matter were of a lucid nature. But how the matter should divide itself into two sorts; and that part of it which is fit to compose a shining body should fall down into one mass and make a sun; and the rest, which is fit to compose an opaque body, should coalesce, not into one great body, like the shining matter, but into many little ones; or if the sun were at first an opaque body like the planets, or the planets lucid bodies like the sun, how he alone should be changed into a shining body, whilst all they continue opaque; or, all they be changed into opaque ones, whilst he remains

* Replique de M. Clarke. Leibnitz, Op. ii. 193.

unchanged; I do not think explicable by mere natural causes, but am forced to ascribe it to the counsel and contrivance of a voluntary agent*."

Such was the conjecture of Newton in accordance with the existing state of philosophical views. He considered the phenomena " not explicable by mere natural causes," and therefore had recourse to a supernatural cause. But supposing the case allowed to be thus unexplained by any known natural causes, we have still to observe that it would afford no more evidences of supernatural agency than simply that which is furnished by the observed facts of the adaptation of the masses and respective physical conditions of the sun and of the planets to each other; and this evidence is unaltered whether the observed fact can be accounted for or not. And if it could be accounted for on any known physical principle, so far from detracting from the manifestation of design, this would only the more augment our impression of widely-pervading skill and recondite adjustment throughout the planetary world. But though we should admit that no cause has been assigned, it would be manifestly contrary to every principle of the inductive philosophy to affim that none can or will be.

When, therefore, we find Laplace suggesting what is, after all, professedly but a conjecture as to the probable course, merely, which inquiry might pro

* Letter I. to Bentley. Works, vol. iv., p. 430.

perly take on such a question, it ought neither to be regarded (as it has been,) as an unwarrantable extension of philosophical analogy, nor dreaded (as in some instances,) as in the least degree hostile to the argument for design; so far from this, if verified, it would but enhance the value of that argument. He, in fact, simply suggests," amid these uncertainties the wisest course would be to devote ourselves to determining, by repeated experiments, the laws of affinity, in order to arrive at what would appear the simplest means of comparing these forces with that of gravitation."

If any law of affinity should ever be developed to such an extent as in any degree to meet the object here in view, (and we can never say that discovery may not be carried so far,) the only result surely would be the most overpowering conviction of the extension of the same vast unity of design throughout the mechanism of the material system.

The Nebular Hypothesis.

CLOSELY Connected with this last case is the "nebular hypothesis," as it has been called, which has in a more peculiar degree, called forth the censures and obloquy of those who were intent on allowing no secondary means as the instruments or channels of the influence of creative power.

The luminous band called the "milky way," is resolved, by powerful telescopes, into a vast multitude

of stars crowded together in infinitely lengthened perspective, and constituting an immense system of sidereal matter of an extended flat form, within which our planetary system is included, and of which our sun is merely one of the innumerable stars which the entire mass.

make up

In various parts of the heavens the telescope discloses to us patches of diffused luminous matter called "nebulæ," bearing a general resemblance in appearance to the milky way as seen by the naked eye. Some of these are found by very powerful telescopes to consist of numerous stars, mostly appearing in the midst of a mass of diffused light. In some cases, the starry points are brilliant and defined; in others, more diffused, or merely points of greater luminous intensity than the surrounding region. Calculation assures us of the inconceivable distance from us beyond which they are situated, and measurement by consequence teaches us their enormous magnitude: so vast, that in many of them not only the solar system, but the whole mass of the milky way to which it belongs, would be lost. Thus we find, as far as observation can be carried into the vastness of the universe, besides distinct stars, an infinity of other systems of stellar matter, in the form of these "nebula," dispersed through space, and of which our entire system, included in the "nebula" to which it belongs, forms but one of the most insignificant.

We have also remarked the different states of

diffusion in which these various nebulæ, with their stellar points, appear to exist.

So far exact observation has led us to the admission of facts which, however overwhelming to our conceptions, are nevertheless beyond question. Now philosophical conjecture has been applied to these facts; and, upon very reasonable analogy, astronomers have indulged in the contemplation of these different forms in which sidereal matter is presented to us, as exhibiting so many different stages in the progress of the formation of sidereal systems.

In the first instance, such matter seems to assume the form of a faint diffused nebulosity. In the next, some of these masses appear as if, in obedience to attractive forces, they had assumed a spherical figure; others, as if further advanced, have a denser central nucleus, surrounded by the more diffuse and yet uncondensed portion; others again, (to use the words of an eminent writer,) "in which the apparently unformed and irregular mass of nebulous light is just curdling, as it were, into separate systems." And further, there are some in a more complete condition, presenting a congeries of distinct points of light, each, perhaps, the sun of a system more vast and glorious than our own, but invisible to us; whilst in the case of the actual systems of double and triple stars, whose motions have been actually observed and calculated, we find the exact counterparts of our own planetary world, which have arrived at a corresponding point in the history of their con

« AnteriorContinuar »