T. S. Eliot's Objective Theory essentially states that a poem or piece of literature should have a sense of inevitability. The idea is that the feelings and emotions should be clear and directly linked with actions, to the point where the outcome is a logical conclusion and understanding of the individual's emotions or motivations. In terms of a poem, while the emotions and experiences of the poet are all swirling around as a many-layered thing, the final result should be a cohesive expression of a unified idea. A poem should express one concept or emotion. It can be an incredibly unique and complex one, but there should be an overarching tone or mood to a successful piece of poetry.
In terms of storytelling, there should be objective and clear motivations and emotions. Eliot analyzes the play Hamlet and concludes that the character of Hamlet is poorly written, because his emotions and choices are not indicative of the events that happen to him in the story. Lady Macbeth is juxtaposed against this, though, as someone that is successfully written—the events of the story lead to a natural response, and the reader or observer can relate and, presumably, would take similar actions given the same set of circumstances.