Plotinus is a writer from the third century CE who engaged in reflection on and philosophical critiques of Plato, thus fashioning himself a Neoplatonist. These writings are titled the Enneads by virtue of having been published by Porphyry (later in the third century) having divided the fifty-four treatises into nine (Greek: “ennea”) groups of six precepts each.

There are several primary aims of the Enneads. One is to validate and extend Plato’s conceit of the difference between forms and reality as well as the concept of “goodness.” Plato (who lived in the fifth century BCE) was a watershed thinker in antiquity for believing that abstract thoughts can be modeled as ideas (or “Forms”). Plotinus extends this theory of Forms to introduce his concept of "the One," a supernatural being from which all things emanate. Like Plato, Plotinus was a metaphysical philosopher who believed that human experience can be divided into and discussed in terms of the One (or "the Good"), the Soul (Greek: "Psuche"), and Mind (Greek: "Nous"). All of human experience, according to Plotinus, can be explained by means of one of these concepts. Plotinus is less concerned with the individual experience as with the idea of being and the unifying principle that obtains to all living things (including humans, plants, and matter). Plotinus also distinguished (like Plato) between the ontological (viz., the theoretical nature of being) and empirical (observed experience). By giving an elegant organization to these ideas, Plotinus's text championed Plato's ideas for his third-century audience (and beyond). The second major significance of the Enneads is as mystical textual guide to recipients of the idea of the One. In addressing itself to initiates in this way, Plotinus's text serves as a guide to his readers to address themselves to the spiritual world, and he himself proposes, acting in much the same way as the Eleusinian rites initiated people yet unacquainted with the Eleusinian mysteries (a set of secret rites established to celebrate the cult of Demeter and Persephone, for which people traveled to the town of Eleusis outside of Athens. To this day, little is know about exactly how these rites were conducted in antiquity).