I don't know if they can be called "theorists of cinema". To me, these two people master the craft (of writing at least).
John Truby calls this person "storyteller". It can be one of the characters or not. In "The Anatomy of Story", he says:
"The storyteller is one of the most misused of all techniques, because
most writers don't know the implications of the storyteller or its
The vast majority of popular stories in movies, novels and plays don't
use a recognizable storyteller. They are linear stories told by an
omniscient storyteller. Someone is telling the story, but the audience
doesn't know who and doesn't care. These stories are almost always
fast, with a strong, single desire line and a big plot.
A storyteller is someone who recounts a character's actions, either in
the first person -- talking about himself -- or in the third person --
talking about someone else. Using a recognizable storyteller allows
you greater complexity and subtlety. Stated simply, a storyteller lets
you present the actions of the hero along with commentary on those
A storyteller also lets the audience hear the voice of the character
who is doing the telling. People bandy about the term "voice" all the
time, as if it were some golden key to great storytelling. When we
talk about letting the audience hear the character's voice, we are
really putting the audience in the character's mind, right now as he
speaks. It is a mind expressed in the most precise and unique way
possible, which is what the character talks about and how he says it.
Being in the character's mind implies that this is a real person, with
prejudices, blind spots, and lies, even when he isn't aware of them
himself. This character may or may not be trying to tell the truth to
the audience, but whatever truth comes out will be highly subjective.
This is not the word of God or an omniscient narrator."
Robert McKee calls him "narrator", or "voice-over". Robert McKee prefers to show instead of telling, and to cut what can be cut, following the "less is more" principle.
McKee says in "Story":
"Voice-over narration is yet another way to divulge exposition. Like
the Flashback, it's done well or ill. The test of narration is this:
Ask yourself, "If I were to strip the voice-over out of my screenplay,
would the story still be well told?" If the answer is yes ... keep it
in. Generally, the principle "Less is more" applies: the more
economical the technique, the more impact it has. Therefore, anything
that can be cut should be cut. There are, however, exceptions. If
narration can be removed and the story still stands on its feet well
told, then you've probably used narration for the only good reason --
Counterpoint narration is Woody Allen's great gift. If we were to cut
the voice-over from HANNA AND HER SISTERS or HUSBANDS AND WIVES his
stories would still be lucid and effective. But why would we? His
narration offers wit, ironies, and insights that can't be done any
other way. Voice-over to add nonnarrative counterpoint can be
You can find them here: Robert McKee and John Truby
- Cinema Paradiso,
- The Shawshank Redemption,
- Heart of Darkness (with three narrators),
- It's a Wonderful Life,
- The Great Gatsby,
- The Usual Suspects.
I hope to have understood your question well.