Ennead III.4: On Our Allotted Guardian Spirit is a lively and at times perplexing text combining general reflections on the nature of the soul with a discussion of the phenomenon of a personal guardian spirit. Plotinus wants to interpret Plato, and aims to integrate Plato’s various statements about daimones into one comprehensive theory.

This leads to some views that are, if not exotic, then at least strange on first encounter. However, a closer reading reveals that Plotinus is not interested in demonology per se. Instead, the central concern of the treatise are ideas about the soul, the self, and self-consciousness. The introduction offers an overview of ancient demonologies, starting with Homer and the Presocratics, and is followed by an in-depth examination of Plato, the Stoics, Plotinus, and later Neoplatonic developments. As such the book presents Plotinus’ specific rationalizing response to the idea of a guardian spirit in the context of ancient philosophical demonologies.

Plotinus was a Platonist, committed to expounding the doctrines put forward by Plato some seven centuries earlier. He was born and educated in Egypt, where he studied the teachings of Plato under the guidance of Ammonius Saccas. He came to Rome in 244 CE and built up a circle of followers devoted to studying Plato through Plato's own works and those of philosophers, both Platonist and non-Platonist, of the intervening centuries. From his fiftieth year Plotinus himself wrote down, in Greek, the findings of the seminars, and these writings were later edited by one of his pupils, Porphyry, and published in six groups of nine treatises entitled the Enneads (from the Greek word for nine – ennea).