74. I am aware, dear brethren, that there are some who confess the likeness, but deny the equality. Let them speak as they will, and insert the poison of their blasphemy into ignorant ears. If they say that there is a difference between likeness and equality, I ask whence equality can be obtained? If the Son is like the Father in essence, might, glory and eternity, I ask why they decline to say He is equal? In the above creed an anathema was pronounced on any man who should say that the Father was Father of an essence unlike Himself. Therefore if He gave to Him whom He begat without effect upon Himself a nature which was neither another nor a different nature, He cannot have given Him any other than His own. Likeness then is the sharing of what is one’s own, the sharing of one’s own is equality, and equality admits of no difference44 Proprietas, or sharing one’s own. The word proprietas is not here used in a technical sense. In its technical sense proprietas or ἰδιότης signifies the special property of each Person of the Godhead, and the word is used to secure the distinctions of the three Persons and exclude any Sabellian misunderstanding.. Those things which do not differ at all are one. So the Father and the Son are one, not by unity of Person but by equality of nature.
74. Similitudinem sine aequalitate confitentes refelluntur.---Nec me fallit, Fratres charissimi, quosdam esse, qui similitudinem confitentes, negant aequalitatem. Sed loquantur ut volunt, et blasphemiae suae virus ingerant ignorantibus. Si inter similitudinem 0529A et aequalitatem differre dicunt; quaero unde comparetur aequalitas. Namque si secundum essentiam et virtutem et gloriam et tempus Patris Filius similis est; interrogo ex quo non videatur 504 aequalis. Nam etiam haec in superiori fide constituta damnatio est: ut anathema esset, qui Patrem dissimilis sibi essentiae diceret patrem. Si ergo naturam neque aliam, neque dissimilem ei, quem impassibiliter generabat, dedit; non potest aliam dedisse, nisi propriam. Ita similitudo proprietas est, proprietas aequalitas est, et aequalitas nihil differt. Quae autem nihil differunt, unum sunt; non unione personae, sed aequalitate naturae.