Pixar was influenced by Robert McKee. https://youtu.be/kpN7KeWfbmE?t=18

His book "Story: Substance, Structure, Style and the Principles of Screenwriting" was popular reading at Pixar back in the Toy Story days.

https://www.amazon.com/Story-Substance-Structure-Principles-...

Robert McKee wrote an incredibly famous book called, Story: Substance, Structure, Style and the Principles of Screenwriting [1]. I've had multiple people stop me on the street as I was carrying it and remark of how great a book it was. It should answer most of your questions.

[1] https://www.amazon.com/Story-Substance-Structure-Principles-...

http://en.wikipedia.org/wiki/Dramatic_theory

http://en.wikipedia.org/wiki/Poetics_(Aristotle)

http://www.amazon.com/Story-Substance-Structure-Principles-S...