Part I
What is the Tao? The Tao, also called “the act of existence (actus essendi),” “the first principle of Zen,” and the region on the other side of Aldous Huxley’s doors of perception, is the nameless reality that is logically, conceptually, and in reality prior to everything else. This part of ESB emphasizes “The Reality Spectrum”: The Tao-->Essence-->Existence. The left hemispheres of our brains emphasize essence (traits, characteristics . . . things it can grasp). Our right hemispheres incline more toward the Tao.
Part II
What is the Great Rejection? Modernity rejected the Tao portion of the Reality Spectrum and focused almost exclusively on the “essence” part of the Reality Spectrum: things we can count, measure, and understand through reason and logic. This rejection of the Tao is the "Great Rejection.” Part II could be called "Modernity." It could also be called "The Rebellion of the Left Hemisphere and Rise of Its Resulting Gnostic Legions."
Part III
What is the Rejection of the Great Rejection? Reality can’t be denied so the Tao keeps bubbling to the surface, often in troubling, but occasionally good ways, as people, either purposefully or intuitively, reject the Great Rejection and the Tao reasserts itself. Part III could be called "Post-Modernity." It could also be called "The Right Hemisphere Strikes Back." The Star Wars wink is unfortunate, since the Empire, in our story, would be a left-hemispheric force, but so be it.
Part IV
How do I get the Tao back into my life? This part could also be called, “How to flourish in modernity despite modernity.” It features a lot of advice for re-asserting one’s right hemisphere (our modem for the Tao and, therefore, “ground zero” for our fight against modernity). Part IV could also be called "How to put your right hemisphere back into its rightful master role."
Part V
Those men and women with strong, but loyal, left hemispheres and equally strong right hemispheres: the saints.