St.
Ambrose has here rendered into Latin the anathema appended to the
original Nicene Creed of 325 a.d. Notice
“substance or οὐσία.” The
original is substantia vel οὐσίᾳ. The
closer Greek equivalent of substantia is ὑπόστασις (found
in Heb. i. 3, and translated “person” in
A.V.), whilst the Latin for οὐσία is
essentia (“essence”). St. Ambrose appears to
regard οὐσία as a proper
equivalent of substantia, whence we may perhaps infer that he
also identified οὐσία and ὑπόστασις in
meaning. But some distinguished the two, using the term
οὐσία
in the sense of “essence” or “substance”
(i.e., the Godhead) and ὑπόστασις in
that of “person”—so that, according to them, there
would be three “hypostases” in the unity of the
Godhead.