A Dictionary of Early Christian Biography 
Damianus (2), M. [See Cosmas.]
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
Monophysite patriarch of Alexandria (t 601), expressed himself on the doctrine of the Trinity in a sense similar to that of Sabellius. He maintained that the divinity ( Θεύτης ) of the Father, the Son, and the Holy Ghost is an essential characteristic ( Ὕπαρξις ) divided among the three, so that they are God only in their unity, not each one in himself ( Καθ᾿ Ἑαυτόν ), and that in this unity they constitute the one divine essence ( Μίαν Οὐσίαν Καὶ Φύσιν ). His followers were called Damianites, after him, or Angelists, from Angelium, the place where they held their assemblies in Alexandria; their adversaries were called Tetradists ( Τετραδίται ), as, going still further than the Tritheists, they acknowledged four gods, namely, the Father, the Son, the Holy Ghost, and the higher Being, which, in his nature ( Φύσει ) and in himself ( Καθ᾿ Ἑαυτόν ), is God. — Herzog, Real- Encyklopadie , 3, 263; Mosheim, Ch. History , bk. ii, ch. vi, pt. i, § 4; Hagenbach, Hist . Of Doctrines , § 96.