3 There is another, who is a renowned teacher among them, and who, struggling to reach something more sublime, and to attain to a kind of higher knowledge, has explained the primary Tetrad as follows: There is [he says] a certain Proarche who existed before all things, surpassing all thought, speech, and nomenclature, whom I call Monotes (unity). Together with this Monotes there exists a power, which again I term Henotes (oneness). This Henotes and Monotes, being one, produced, yet not so as to bring forth [apart from themselves, as an emanation] the beginning of all things, an intelligent, unbegotten, and invisible being, which beginning language terms “Monad.” With this Monad there co-exists a power of the same essence, which again I term Hen (One). These powers then— Monotes, and Henotes, and Monas, and Hen— produced the remaining company of the Æons.
Source: Adversus haereses (New Advent)