Henology (from Greek ἕν hen, "one") is 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."

Henology (from Greek ἕν hen, "one") is 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."