It is impossible that they should be other than they are.
But what is the meaning of all this?
Plainly that the solar system is not interrupted by providential interventions, but is under the government of irreversible law--law that is itself the issue of mathematical necessity.
The telescopic observations of Herschel I.satisfied him that there are very many double stars--double not merely because they are accidentally in the same line of view, but because they are connected physically, revolving round each other.

These observations were continued and greatly extended by Herschel II.

The elements of the elliptic orbit of the double star zeta of the Great Bear were determined by Savary, its period being fifty-eight and one-quarter years; those of another, sigma Coronae, were determined by Hind, its period being more than seven hundred and thirty-six years.

The orbital movement of these double suns in ellipses compels us to admit that the law of gravitation holds good far beyond the boundaries of the solar system; indeed, as far as the telescope can reach, it demonstrates the reign of law.

D'Alembert, in the Introduction to the Encyclopaedia, says: "The universe is but a single fact; it is only one great truth." Shall we, then, conclude that the solar and the starry systems have been called into existence by God, and that he has then imposed upon them by his arbitrary will laws under the control of which it was his pleasure that their movements should be made?
Or are there reasons for believing that these several systems came into existence not by such an arbitrary fiat, but through the operation of law?
The following are some peculiarities displayed by the solar system as enumerated by Laplace.