Winter brings on cold weather; and we must shiver. Summer returns, with its heat; and we must sweat. Unseasonable weather upsets the health; and we must fall ill. In certain places we may meet with wild beasts, or with men who are more destructive than any beasts. Floods, or fires, will cause us loss. And we cannot change this order of things; but what we can do is to acquire stout hearts, worthy of good men, thereby courageously enduring chance and placing ourselves in harmony with Nature. And Nature moderates this world-kingdom which you see, by her changing seasons: clear weather follows cloudy; after a calm, comes the storm; the winds blow by turns; day succeeds night; some of the heavenly bodies rise, and some set. Eternity consists of opposites. It is to this law that our souls must adjust themselves, this they should follow, this they should obey. Whatever happens, assume that it was bound to happen, and do not be willing to rail at Nature. That which you cannot reform, it is best to endure, and to attend uncomplainingly upon the God under whose guidance everything progresses, for it is a bad soldier who grumbles when following his commander. For this reason we should welcome our orders with energy and vigor, nor should we cease to follow the natural course of this most beautiful universe, into which all our future sufferings are woven.
– Letter CVII