As an example, do you mean 'grief' for characterA and 'struggle with honesty' for characterB? Then you map out the specific scenes that reflect these struggles?
I connect through-lines with themes, so with your indulgence I need to talk about them both together. This is a personal view. I've yet to find two writers who think of this stuff the same way, or a book that covers it the way I'd like to see it covered.
So firstly, what is a theme?
What is a Theme? (Ruv's take)
In music, a theme is an idea that's repeated and varied. Sometimes it's played by a single instrument, sometimes more than one together... Sometimes a theme is played on its own, sometimes in counterpoint with some other theme. I think in literature it's the same. A theme is more than just a repeated image or motif -- it's an idea that the story plays with. In literature, the 'instruments' that play themes are the major characters. Just as in music they can play a theme together, or swap themes, or vary themes... which is part of what gives literature its passion and beauty.
Where plot is about motives and goals, themes are about a character's
ruling passions -- what gets them fired up, and how, and what comes of that.
What is a Through-line? (Ruv's take)
If you recall that a
log-line is about goals, a
through-line is about the ruling passions underpinning those goals. So a log-line carries plot while a through-line carries theme, and the two tend to run in lock-step.
As I mentioned, a convenient format for a log-line is character in
situation has
objective but encounters
opposition with a risk of
disaster. Similarly
, a convenient format for stating through-line is:
For character(s), passion leads from emotion1 to emotion2.
As a log-line forms part of plot, so a through-line forms part of theme. Example:
For Cinderella, humility leads from humiliation to joy;
for Hansel and Gretel, greed leads from bravery to terror.
In Cinderella we see themes of pride vs humility. Cinderella's humility is counterpointed with the ugly step-sisters' pride. In the end though, Cinderella becomes the grandest of all.
In
Hansel and Gretel we see themes of bravery and greed vs prudence. Hansel and Gretel's bravery and greed lead them to almost being devoured by the witch, but their bravery and prudence see them escape.
Related to through-line is the
character arc which are just the end-points of the journey:
emotion1 and
emotion2. So Cinderella's character arc is :
humiliation à joy.
So everything is inter-linked: The character arc tells us there's an emotional change. The through-line tells us what ruling passion drives the change and the plot tells us how this change occurs.
Often characters' ruling passions change too, and to track that, we can write a through-line in several clauses, e.g.
For Snow White, innocence leads from trust to misery, but kindness leads from misery to joy;
For Little Red Riding Hood, innocence leads from trust to betrayal, but faith leads from betrayal to relief.
As I mentioned, 'how' of this progression emerges from plot. E.g. Snow White's ruling passion of Innocence makes her vulnerable to the machinations of the Wicked Queen. But with her Innocence comes Kindness -- as seen in her treatment of the dwarves, and in the way her beauty reflects her heart. So even the Wicked Queen's poison cannot remain forever lodged in her throat.
You'll notice that in these fables there's a moral -- and the moral looks an awful lot like the themes. Which I think is as it should be.
Which comes first: Characters? Themes? Plots?
I think it doesn't matter.
If we have themes, we can create characters and plot to embody those themes. E.g. If I have in themes 'treachery leads from greed to humiliation', then I can create a character who's an
extreme of type in treachery, and then find a situation where he'll betray for greed, and then find someone with means to create a disaster that humiliates my character -- then contrive to give him motive and opportunity.
If we have plot, we can find themes just by finding the
character arcs and
ruling passions of our characters. And if our arcs and ruling passions aren't strong enough, we can use this exercise to strengthen them -- usually by making the characters and situations more
extreme.
If we have characters then we can toy with ideas for theme and plot. E.g. if one character is notably gluttonous and another is notably cowardly, what might come of that? How can Iwe put them into counterpoint? Will either character change over time? Will that be to the character's weal or woe?
I think it's for this reason that some authors say that themes emerge organically from (good) stories -- because authors who start with characters or plots will often find their themes along the way. But some authors can start from themes and build stories too.
I often like to sketch my themes out early and let that inform my characters and plots. One benefit of this is that the
mood and
motifs -- the emotions and imagery that decorate our settings -- can be chosen to enhance my themes. For me, this just creates a more rich and satisfactory first draft. But even if we skip themes in the first draft, we can always find them later.
How do you know if your story has themes?
If your story has
ruling passions in its major characters, and strong
character arcs I think it's guaranteed to have themes -- even if it has the sketchiest plot. In better-quality published fiction we can see both plot and theme emerging in the opening paragraphs. Here's Jane Austen in
Pride and Prejudice, for instance.
Pride and Prejudice said:
It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife.
However little known the feelings or views of such a man may be on his first entering a neighbourhood, this truth is so well fixed in the minds of the surrounding families, that he is considered the rightful property of some one or other of their daughters.
These opening lines establish a
ruling passion -- a passion for Fitting Matrimony, which ends up becoming a driver for the story's themes of matrimonial propriety. It also establishes the beginnings of plot -- even before a single character appears. We know that someone will want a man to marry, and that he may not want to be wed as others choose.
Here's the opening for Bram Stoker's
Dracula -- it's longer, more subtle, but I think it's worth the read:
3 May. Bistritz.--Left Munich at 8:35 P.M., on 1st May, arriving at Vienna early next morning; should have arrived at 6:46, but train was an hour late. Buda-Pesth seems a wonderful place, from the glimpse which I got of it from the train and the little I could walk through the streets. I feared to go very far from the station, as we had arrived late and would start as near the correct time as possible.
The impression I had was that we were leaving the West and entering the East; the most western of splendid bridges over the Danube, which is here of noble width and depth, took us among the traditions of Turkish rule.
We left in pretty good time, and came after nightfall to Klausenburgh. Here I stopped for the night at the Hotel Royale. I had for dinner, or rather supper, a chicken done up some way with red pepper, which was very good but thirsty. (Mem. get recipe for Mina.) I asked the waiter, and he said it was called "paprika hendl," and that, as it was a national dish, I should be able to get it anywhere along the Carpathians.
I found my smattering of German very useful here, indeed, I don't know how I should be able to get on without it.
Having had some time at my disposal when in London, I had visited the British Museum, and made search among the books and maps in the library regarding Transylvania; it had struck me that some foreknowledge of the country could hardly fail to have some importance in dealing with a nobleman of that country.
I find that the district he named is in the extreme east of the country, just on the borders of three states, Transylvania, Moldavia, and Bukovina, in the midst of the Carpathian mountains; one of the wildest and least known portions of Europe.
I was not able to light on any map or work giving the exact locality of the Castle Dracula, as there are no maps of this country as yet to compare with our own Ordance Survey Maps; but I found that Bistritz, the post town named by Count Dracula, is a fairly well-known place. I shall enter here some of my notes, as they may refresh my memory when I talk over my travels with Mina.
In the population of Transylvania there are four distinct nationalities: Saxons in the South, and mixed with them the Wallachs, who are the descendants of the Dacians; Magyars in the West, and Szekelys in the East and North. I am going among the latter, who claim to be descended from Attila and the Huns. This may be so, for when the Magyars conquered the country in the eleventh century they found the Huns settled in it.
I read that every known superstition in the world is gathered into the horseshoe of the Carpathians, as if it were the centre of some sort of imaginative whirlpool; if so my stay may be very interesting. (Mem., I must ask the Count all about them.)
I did not sleep well, though my bed was comfortable enough, for I had all sorts of queer dreams. There was a dog howling all night under my window, which may have had something to do with it; or it may have been the paprika, for I had to drink up all the water in my carafe, and was still thirsty. Towards morning I slept and was wakened by the continuous knocking at my door, so I guess I must have been sleeping soundly then.
This is written from a Main Character's viewpoint... we learn that his ruling passion is associated with Modernity (see his concern for punctuality, his open-mindedness about travel, and his scorn for backwater countries). But see also how in counterpoint, the place Jonathan Harker travels is all about lust, ignorance and torment -- thirst, bad maps and bad dreams. This paves the way for Count Dracula's ruling passions. Naturally too, the opening also establishes plot -- Jonathan is falling into Dracula's power.
Conclusion
So, in my take, themes are tied to ruling passions and character arcs; and plots are the vehicle passions use to move characters along. So it's all connected and we can literally start wherever we like. But log-lines and through-lines are the methods I find most useful for keeping track of it all. If you know the log-lines you have a fair understanding of your plot; if you know your through-lines then you have a fair understanding of your character arcs and themes.
Hope that helps demystify things a little.