The narrator returns to Ishmael's office ready to explain the middle and end of the story of Taker culture. He says the middle of the story is humankind's time as hunter-gatherers, a time when they were living much as other animals do. But, for humankind to achieve its destiny, it had to discover agriculture, which provided it with the means of staying in one place and developing civilization and technology.
Ishmael is impressed with the narrator's ability to distinguish this part of the story, but he pushes the narrator to continue: so why must man do this? What's the purpose of rising above the other animals? Ishmael has the narrator imagine an Earth without humans on it; the narrator imagines a wild jungle and admits he'd be reluctant to live in such a world as he'd be at the mercy of fierce predators. Thus, Ishmael helps the narrator see the next part of the story: man was put on Earth to rule it, and to do so he had to conquer it. At this point, the narrator admits his astonishment because he realizes that all around him he hears about man conquering things — from deserts to outer space.
But this isn't enough for Ishmael. He pushes the narrator to think on it more deeply. The narrator realizes that while the Taker cultural story suggests that things are the way they are because man had to fulfill his destiny of conquering everything, really things are the way they are because man hasn't become the ruler of the world, but its destroyer and enemy.
In Part 4, Quinn establishes Ishmael and the narrator as archetypes rather than fully developed characters and addresses the novel's central question regarding the current state of the world. To begin, Part 4 makes it clear that Ishmael and the narrator will not develop the way characters might in a typical plot-driven novel. For instance, little happens outside their discussions, besides small movements, like Ishmael chewing on a leafy branch. By stripping down the characters and their setting to the bare essentials, Quinn establishes Ishmael and the narrator as an archetypal teacher and student. Ishmael has all the qualities of a skilled teacher: he's calm, patient, informative, and encourages participation on the part of his student. Similarly, the narrator is an ideal student: he's inquisitive, eager to learn, and willing to deeply engage with the material his teacher presents him. By depriving his central characters of excessive physical and emotional detail, Quinn focuses the novel around its philosophical discoveries rather than the development of a traditional plotline.
The novel's central question and theme — why are things the way they are — evolves in Part 4 through Ishmael's use of imaginative exercises and Socratic dialogue. To begin, Ishmael encourages the narrator to imagine Earth without man. Through this creative exercise, the narrator sees the world in a new way and better understands his culture myth — that man has evolved to conquer the Earth. Additionally, Ishmael illustrates his points through further questioning of the narrator. For instance, by asking the narrator to explain how Takers justify the destruction of the world's natural resources and wildlife, the narrator says that Takers would see this as the price that must be paid to advance human culture. Ishmael uses the narrator's response to build to his next point: that the Takers have it wrong — that they are paying the price it costs to be "the enemy of the world."