Mutual interference in the particles outside the mass of the sun prevents all accumulation except in one plane and that takes the form of a thin disk continuous with the sun's equator. In this circulating vaporous disk about the sun differences of density give rise to zones not unlike the rings of Saturn. These zones ultimately contract to form planets, and as the planets are thrown off from the central solar mass till an equilibrium is established between the centripetal and centrifugal forces, so the satellites in turn are formed from the planets. The comets are to be regarded as parts of the system, akin to the planets, but more remote from the control of the centripetal force of the sun. It is thus that Kant conceived the nebular hypothesis, accounting (through the formation of the heavenly bodies from a cloudy vapor similar to that still observable through the telescope) for the revolution of the planets in one direction about the sun; the rotation of sun and planets; the revolution and rotation of satellites; the comparative densities of the heavenly bodies; the materials in the tails of comets; the rings of Saturn, and other celestial phenomena. Newton, finding no matter between the planets to maintain the community of their movements, asserted that the immediate hand of God had instituted the arrangement without the intervention of the forces of Nature. His disciple Kant now undertook to explain an additional number of phenomena on mechanical principles. Granted the existence of matter, he felt capable of tracing the cosmic evolution, but at the same time he maintained and strengthened his religious position, and did not assume (like Democritus and Epicurus) eternal motion without a Creator or the coming together of atoms by accident or haphazard.
It might be objected, he says, that Nature is sufficient unto itself; but universal laws of the action of matter serve the plan of the Supreme Wisdom. There is convincing proof of the existence of God in the very fact that Nature, even in chaos, cannot proceed otherwise than regularly and according to law. Even in the essential properties of the elements that constituted the chaos, there could be traced the mark of that perfection which they have derived from their origin, their essential character being a consequence of the eternal idea of the Divine Intelligence. Matter, which appears to be merely passive and wanting in form and arrangement, has in its simplest state a tendency to fashion itself by a natural development into a more perfect constitution. Matter must be considered as created by God in accordance with law and as ever obedient to law, not as an independent or hostile force needing occasional correction. To suppose the material world not under law would be to believe in a blind fate rather than in Providence. It is Nature's harmony and order revealed to our understanding that give us a clue to its creation by an understanding of the highest order.