What is "henology"

n. The philosophical discourse on "The One" that appears most notably in the philosophy of http://en.wikipedia.org/wiki/Plotinus.

Henology (from Greek ἕν hen, "one") refers to the philosophical account or discourse on "The One" that appears most notably in the philosophy of Plotinus. Reiner Schürmann describes it as a "metaphysics of radical transcendence" that extends beyond being and intellection. It can be contrasted with ontology, as ontology is "an account of being" whereas henology is an "account of unity."