Treatise?

Treatise, according to Webster, is a systematic exposition or argument in writing including a methodical discussion of the facts and principles involved and conclusions reached. Simply put, it is a written work dealing formally and systematically with a subject.

Now, I'd like to explore some of Steinbeck's tactics in The Grapes of Wrath. I saw him as systematic as the big machines plowing straight lines no matter the obstacle. He is telling a story from the perspective of these migrants, not stating facts and principles as the above definition requires. He probes the fears and anger of his characters allowing the reader to build his or her own emotional reaction; human emotions are rarely methodical and systematic.

I do believe he had a strong anti-establishment (machine, bank, etc.) intent, but was far from a statistical diatribe with his in-depth trade of emotions between characters. Grandpa died. With no immediate emergency medical car, a fact of the time is that many family members died at home or at least around family. The family came up with a plan but not systematically, they bantered with emotion, then facts of money and procedure, then emotion again, and back to reality of their situation. The previous two sentences were a treatise of the death and burying of Grandpa. Steinbeck wrote of  the turmoil of "doing what's right" for family and the hard facts of their money situation preventing it. The reader can convey the emotional pain of what to do for Grandpa. Emotions are not formal, systematic, nor methodical discussions of facts that gives a solid conclusion. Each reader will react differently from personal frame of reference. I don't believe this choice would be involved in a treatise.