XXVI. (87) And on this account too Moses calls the sabbath, which name being interpreted means “rest,” “the sabbath of God.”{25}{#le 23:2.} Touching upon the necessary principles of natural philosophy, not of the philosophy of men, in many parts of his law, for that among existing things which rests, if one must tell the truth, is one thing only, God. And by “rest” I do not mean “inaction” (since that which is by its nature energetic, that which is the cause of all things, can never desist from doing what is most excellent), but I mean an energy completely free from labour, without any feeling of suffering, and with the most perfect ease; (88) for one may say, without impropriety, that the sun and the moon, and the entire heaven, and the whole world labour, inasmuch as they are not endowed with independent power, and are continually in a state of motion and agitation, and the most undeniable proofs of their labour are the yearly seasons; for these things, which have the greatest tendency in the whole heaven to keep things together, vary their motions, making their revolutions at one time northern, at another time southern, and at other times different from both. (89) The air, again, being sometimes warmed and sometimes cooled, and being capable of every sort of change, is easily proved to labour by the variations to which we feel that it is subject, since the most general cause of change is fatigue, and it would be folly to enter into any long detail about terrestrial or aquatic animals, dwelling at any length upon their general or particular changes; for these animals very naturally are liable to weakness in a much greater degree than those sublime objects, inasmuch as they partake to the greatest extent of the lowest, that is of earthly essence. (90) Since therefore it is naturally the case that things, which are changed, are changed in consequence of fatigue, and since God is subject to no variation and to no change, he must also by nature be free from fatigue, and that, which has no participation in weakness, even though it moves everything, cannot possibly cease to enjoy rest for ever. So that rest is the appropriate attribute of God alone.