Book excerpt: This early treatise is placed by Plotinus’ editor at the very end of the Enneads, as the culmination of his thought, matching Plotinus’ own last recorded instruction, “to bring the god in you back to the god in the all.” It is a cosmological sketch, arguing that the being of anything depends on its being unified by its orientation to its own good, and so also the being of Everything, the All. The One, or the Good, is at once the goal of all things both individually and collectively, and also the transcendent source of all that we experience, mediated through an intelligible order. But it is also, and perhaps more importantly, intended as a guide to the proper education and discipline of our own motives and experience. We are encouraged to put aside immediate sensory data, egoistic prejudice and sensual impulse, first to grasp at least a little of the intelligible order within which we all live, and at last to purge even those last intellectual attachments and experience what cannot be adequately described: the unity of being.