Freud suggests that the remaining sections of the essay will be speculation—his attempt to follow the path of his initial observation that something beyond the pleasure principle must be impacting human motivation toward a theoretical conclusion. Consciousness is only one part of the psyche, but it plays an important role by turning toward the external reality and responding to it. Both the unconscious and conscious are necessary to navigate and organize the volume of stimuli produced in the external world.

The psychoanalyst provides connections between the nervous system and various regions of the brain to the experience of taking in and translating external stimuli. He views the central nervous system as the primary manager of these stimuli, or “excitations.” The sheer volume of stimuli requires the mind to reduce excitations and achieve balance. An imagined simple living organism offers insight into how all animals, including humans, respond to stimuli. Freud suggests that the goal of all organisms is to maintain equilibrium and balance.

Trauma is excess energy brought on by overwhelming stimuli. Freud proposes that trauma often occurs when an outward manifestation of the experience does not occur, such as a wound, during which that energy can be released or when a human does not engage in one of the major stress responses.