HenologyHenology is the philosophical account or discourse on the One that appears most notably in the philosophy of Plotinus.Areas of inquiryHenology stands in contradistinction to several other philosophical disciplines. The term henology refers to the discipline that centers around the One, as in the philosophies of Plato and Plotinus. It is sometimes used in contradistinction to disciplines that treat being as their starting point, and also to those that seek to understand knowledge and truth.