Ennead

The Enneads of Plotinus, as they exist today, are all that were written by Plotinus' student Porphyry. They were quite important at the time, and it is not surprising that they have survived relatively intact. In fact, it is attested elsewhere that Porphyry had to undertake a significant edit to get things to fit into this symmetry, as it was considered at the time in late Classical Greece, of six books of nine lectures each.

En"ne*ad (?), n. [Gr. , , fr. nine.]

The number nine or a group of nine.

The Enneads, the title given to the works of the philosopher Plotinus, published by his pupil Porphyry; -- so called because each of the six books into which it is divided contains nine chapters.

© Webster 1913.