Rufus. From the remarks of Epictetus on friendship
Of such a character the nature of the universe was and is and will be, and it is not possible for things that come into existence to come into existence differently from the way they now do. And in this process of change and transformation, not only human beings and other creatures of earth have had a part, but also the divine beings, and even the four elements are changed and transformed upwards and downwards; that is, earth becomes water and water air, and air is again transformed into ether; and there is the same process of transformation downwards. If a man resolves to focus his thoughts on these things and persuades himself willingly to accept the inevitable, he will lead a life well measured and in harmony with the universe.