Loser's Guide to Life
I was wondering where the term “through line” comes from, because people keep using it as a sort of bludgeon with which to hew their critiques of inexplicable charcters in plays and movies.
I found a source in Daniel Meyer-Dinkgräfe's Approaches to Acting (2001), p. 41:
All elements of the pychotechnique assist the actor's energies to converge towards a holistic and organic expression of a character on the stage. Stanislavsky regards the holistic value of acting on two levels: on the level of action, he coined the phrase “through line of action”. On the level of speech, the equivalent to “through line of action” is called the “subtext”.
Holistic and organic. (....). Anyway, I think some actors might instinctively be doing something other than trying to analyse that. It's more likely that they are thinking of a particular state of mind, or trying to recreate one, and everything else comes from there.
It's really not helpful if you are writing a story about a character, or a story that merely includes characters, because you can observe people doing things in a certain way, and that's pretty much all there is. Anything you add to that just weakens the impression for many readers (or viewers).