
Dialogue: The Art of Verbal Action for Page, Stage, and Screen

All the principles of storytelling combine into the art of dialogue. Dialogue should be changeful, it should want something, it should drip with personality and point of view, and it should operate on the two story levels – both conscious and subconscious.
Will Storr • The Science of Storytelling: Why Stories Make Us Human and How to Tell Them Better
In treatment the writer indicates what characters talk about—“he wants her to do this, but she refuses,” for example—but never writes dialogue.
Robert McKee • Story: Style, Structure, Substance, and the Principles of Screenwriting

we realize that dialogue – and its ability to mask as much as it reveals – is as indispensable a part of structure as character, act division, inciting incident and story.
John Yorke • Into The Woods: How Stories Work and Why We Tell Them
The unique strength and wonder of the novel is the dramatization of inner conflict.
Robert McKee • Story: Style, Structure, Substance, and the Principles of Screenwriting
dialogue is the characters’ responses to the narrative