In the whole of things there is one harmony: and just as all material bodies combine to make the world one body, a harmonious whole, so all causes combine to make Destiny one harmonious cause. Even quite unsophisticated people intuit what I mean. They say: 'Fate brought this on him.' Now if 'brought', also 'prescribed'. So let us accept these prescriptions just as we accept those of Asclepius - many of them too are harsh, but we welcome them in the hope of health.
You should take the same view of the process and completion of the design of universal nature as you do of your own health: and so welcome all that happens to you, even if it seems rather cruel, because its purpose leads to the health of the universe and the prosperity and success of Zeus. He would not bring this on anyone, if it did not also bring advantage to the Whole: no more than any given natural principle brings anything inappropriate to what it governs.
So there are two reasons why you should be content with your experience. One is that this has happened to you, was prescribed for you, and is related to you, a thread of destiny spun for you from the first by the most ancient causes. The second is that what comes to each individual is a determining part of the welfare, the perfection, and indeed the very coherence of that which governs the Whole. Because the complete Whole is maimed if you sever even the tiniest fraction of its connection and continuity: this is true of its constituent parts, and true likewise of its causes. And you do sever something, to the extent that you can, whenever you fret at your lot: this is, in a sense, a destruction.
This passage screams amor fati! People grumble, complain and whine all the time about pretty much anything. I am just as guilty as the next guy of complaining about things. I am writing this post on the evening of September 5, 2017 on the 2nd floor of my home. My entire bottom floor of my home has all the drywall and insulation pulled out. It's as if my home's inner walls have lost their pants - all you see are wood studs. The kitchen is gone, the living, dining and master bed rooms empty of contents. Out front lies the last rubbish pile from the gutting of the bottom floor. I, along with the millions of other south-eastern Texans have survived Hurricane Harvey.
I've learned several things this last week, including one lesson in not complaining. When I hear of the story of a friend of mine whose home was flooded in April of 2016 and he just barely finished the repairs on his home from that flood, only to be flooded yet again; and furthermore, he was just about to buy flood insurance when Harvey hit. His 401K will take another hit like it did in 2016. Or when I hear of another family who was trying to sell their home and live in their new one at the same time, and both homes get flooded and neither home has flood insurance. Or when I hear the stories of family who got swept away in the flood or the toddler clinging to the neck of her dead mother who drowned. In all these cases, I have no room to complain. My family lived; our home is insured. We saved 95% of our possessions.
But what if one of these stories I described above was my story? Would I be justified in complaining? Marcus would say, no. He might even say that Zeus or the universe has prescribed this for us - that our fate is good for us. That is some exceptionally hard philosophy to swallow!
Furthermore, he says that when we do "fret", we are in a sense destroying ourselves. What does this mean? To me, it means that when we complain or fret or are anxious, we are failing to learn how to be more gritty and stronger and enduring. The universe wants this to happen to you and by properly reacting to that fate, you are ennobling the whole.
During this last week, I've had to drive around a lot and I've had to do a lot of heavy lifting and hauling of debris. Almost all during that time, I've been listening to Johnny Cash. One song of his is a really interesting song about how a father named his son Sue and how the son got beat up and made fun of his whole life because of his name. When he finally caught up with his dad, he fought him and was about to kill him when his dad explained why he named him Sue. It was so that he would have a tough life and if he could survive that tough life, he could survive anything. And at that point, his whole perspective changed. It really is a neat little song that encapsulates the idea of amor fati even though the son kinda missed the whole point until he fought his dad. But from the dad's perspective, he was like Zeus prescribing something for the benefit of his son - in this case, he gave his son a girl's name knowing that he'd have to be tough his whole life.
(see also Citadel p. 43, 139-140, 142, 162-163, 221)