Page:The System of Nature.djvu/83

 w mode of existence; which necessarily carries with it a new series of action, a new chain of motion, different from that of which this being found itself susceptible in the preceding rank it occupied. That which is called order, in Nature, is a mode of existence, or a disposition of its particles, strictly necessary. In every other assemblage of causes and effects, of worlds, as well as in that which we inhabit, some sort of arrangement, some kind of order would necessarily be established. Suppose the most incongruous, the most heterogeneous substances were put into activity, and assembled by a concatenation of extraordinary circumstances; they would form amongst themselves, a complete order, a perfect arrangement. This is the true notion of a property, which may be defined, an aptitude to constitute a being, such as it is actually found, such as it is with respect to the whole of which it makes a part.

Order, then, is nothing but necessity, considered relatively to the series of actions, or the connected chain of causes and effects, that it produces in the universe. What is the motion in our planetary system; but a series of phenomena, operated upon according to necessary laws, that regulate the bodies of which it is composed? In conformity to these laws, the sun occupies the centre; the planets gravitate towards it, and revolve round it, in regulated periods: the satellites of these planets gravitate towards those which are in the centre of their sphere of action, and describe round them their periodical route. One of these planets, the earth which man inhabits, turns on its own axis; and by the various aspects which its revolution obliges it to present to the sun, experiences those regular variations which