Perhaps the tragic poet meant the day when he said the sun, inasmuch as it is the cause of the day,—teaching that those things which most need the day and night are the things which are under the moon, and other things in a less degree than those which are upon the earth. Day and night, then, are subject to mortals, being created for the sake of rational beings. And if ants and flies, which labour by day and rest by night, have, besides, the benefit of those things which were created for the sake of men, we must not say that day and night were brought into being for the sake of ants and flies, nor must we suppose that they were created for the sake of nothing, but, agreeably to the design of Providence, were formed for the sake of man.