The View from the C-Series: Ted Chiang's "Story of Your Life"

If I were to say to you that the extinction of feudalism led to the pandemic of the Bubonic Plague, you would tell me that I was wrong and that I had gotten my facts backward: the outbreak of the Plague led to the eventual extinction of feudalism and the invention of a middle class. You would, of course, be correct, assuming we exist in a universe where only the A-series and the B-series are valid perceptions of events in Time.
However, McTaggart, who coined the terms A-series and B-series in his essay “The Unreality of Time” also briefly mentioned the C-series. He described it thus:

But this other series – let us call it the C series – is not temporal, for it involves no change, but only an order. Events have an order. They are, let us say, in the order M, N, O, P. And they are therefore not in the order M, O, N, P, or O, N, M, P, or in any other possible order… And the C series, while it determines the order, does not determine the direction. (461-2)

If I were to attempt to put his ideas graphically, it might look like this:
Past___M___N___O___P___Future (A-series)
Earlier___M___N___O___P___Later (B-series)
___M___N___O___P___ (C-series)
___P___O___N___M___ (Also C-series)
In other words, while both the A-series and the B-series rely on previous events and their effects on later events, the C-series is under no such constraints. In a C-series understanding of the universe, World War I and World War II are related, but neither was the cause nor effect of the other. They simply exist in an order; things like “before” and “after” depend on which side of the event line you are looking from.
Great, you say. But that doesn’t really matter, because in the real world, cause leads to effect. The C-series is an interesting thought experiment, but has no bearing on reality.
The C-series makes a case for humans imposing a timeline, a sense of cause and effect on an otherwise random set of events. Consider this scenario: Someone asks you to recall a very specific Christmas, say the one when you were twelve years old. You go back and think. When you were twelve, you loved Transformers. Your Grandma Monica always gave you a framed poster of your favourite movies for Christmas, but that year, for some reason, Grandma Monica wasn’t at your family’s Christmas party. You remember that, sometime in your early adolescence, your Grandma Monica died in a car accident. You assume that her absence means that she had died before that Christmas occurred, when, in fact, she’d decided on a whim to go on a cruise with her new boyfriend that year. Her death wouldn’t occur until the following February. Grandma Monica’s absence caused a great deal of scandal amongst your aunts and uncles, but you don’t remember that; you have created a series of causes and effects that make sense to you: Grandma Monica always gave you a poster for Christmas; Grandma Monica was not there for that Christmas; Grandma Monica died around that time in your life; Grandma Monica must have been dead for that Christmas.
This holds true with what psychologists have discovered about human memory – that when we pull a memory file to examine, we recreate it from scratch. Every time we try to recall something, we are creating a copy of a copy of the original event. As anyone who has ever tried to make copies of copies of paperwork can tell you, after a certain number of iterations, the copy is completely illegible and nothing like the original.
In fact, psychologists use this fact to help people who suffer from PTSD. By having their patients recall a traumatic memory while in an opposite emotional state, the psychologists are able to recalibrate the neurons associated with that memory, turning the memory from traumatic to manageable. The original event hasn’t changed—only the patient’s experience and memory of it.
Later, you go and ask your mother when your Grandma Monica died. She verifies that Grandma Monica died two months after your twelfth Christmas. She reminds you of Grandma Monica’s boyfriend at the time. You remember, now, your pre-adolescent confusion about Grandma Monica’s absence; you remember the tension around the dinner table. You remember that the following Valentine’s Day was a somber event, because of the car accident.
The C-series is a difficult concept to grasp initially, because we rely so heavily on cause → effect. Sometimes, the best way to understand a difficult concept is to apply it to an enjoyable medium, such as fiction. Ted Chiang’s short story “Story of Your Life”, upon which the film The Arrival was based, is one of the best examples of the C-series idea in science fiction literature. Linguistics! Physics! Aliens! Philosophy of Time! This story has everything science fiction could possibly need, without becoming overwhelming.
The story follows a linguist who has been called upon to interact with an alien species that has landed on Earth. She spends months and months learning how to communicate with them, learning their language and writing system, to the point that she is able to think in their language. It affects the way she understands the universe, leading to beautiful sentences like this:

I remember when you’ll be a month old, and I’ll stumble out of bed to give you your 2:00 am feeding.

After spending many months interacting with an alien species who fails to see the universe as a system of causes and effects, the narrator begins to remember things that have yet to occur. Whereas humans believe that M → N → O, the aliens determine O and extrapolate N → M. No cause or effect, simply an order. A true C-series explanation.
So did the Bubonic Plague lead to the death of feudalism and the birth of the middle class? Did it occur the other way around? Or did both events happen concurrently and historians simply decided that one must have affected the other?
Did Grandma Monica die before your twelfth Christmas, or your thirteenth?
In either case, it doesn’t matter. The Bubonic Plague hit England in 1348, and continued to ravage the island until the 17^th century, well after the establishment of a middle class. The last Christmas you got to see Grandma Monica was when you were eleven. She never came to Christmas again. The reason why is irrelevant.
The brilliance of the C-series lies in its focus on how we interpret distant facts and memories. When faced with a set of discrete facts, the human mind goes and puts them in an A-series or B-series order. The C-series proves that humans thrive as long as we can understand Time as a linear progression of cause and effect, this leading to that.
It shows us that, while we cannot always separate cause from effect, we can impose them as needed to keep a steady understanding of the universe. And that’s a pretty neat trick.