Monoousios vs. Homoousios

Back on May 11th, a good friend of mine began posting again in the Terminology: trinitarianism, unitarianism, monotheism, polytheism... thread, after an extended hiatus. The conversation between the two us continued over the next few days; and then on the 22nd, Tom contributed three consecutive, interrelated posts that would have been a bit difficult to adequately address in the combox. As such, I have created this new thread in an attempt to do justice to the cogent concerns and questions that he raised in those posts.

Now, a bit of background information. For a number of years now, I have maintained that the Greek term homoousion in the Nicene Creed and Chalcedonian Definition was used in a generic sense and not a strict numeric sense—in other words, homoousion is to be understood as 'same essence' rather than 'one essence'. And so, on my May 21st post to Tom, I wrote:

The Greek of the Chalcedonian Definition (451) strongly suggests a generic sense for both. My studies indicate that the numeric sense was not adopted until much later when homoousia began to be interpreted as monoousia. [Note: I had quickly typed up the above response and posted it before realizing that I had misspelled both homoousia and monoousia—should read homoousios and monoousios—sorry Tom, I am getting old.]

Tom on the 22nd responded with:

I would agree that homoousia began to be interpreted as monoousia, but what scholars usually say is “homoousia in the numeric sense.” I have not seen folks who suggest that traditional Christian Trinitarian teachings are true use the term monoousia to describe what they believe. Folks like Plantinga might be inclined to point to the developed equivalence of monoousia and homoousia in the numeric sense, but I don’t see things like this from Father Don Davis or Phillip Schaff.

I first encountered the distinction between monoousios and homoousios in Dr. Charles Hodge's Systematic Theology. Dr. Hodge wrote:

The ambiguity of the word ὁμοούσιος has already been remarked upon. As ούσια may mean generic nature common to many individuals, not unum in numero, but ens unum in multis, so ὁμοούσιος (consubstantial) may mean nothing more than sameness of species or kind. (Charles Hodge, Systematic Theology, Grand Rapids, MI: Eerdmans Publishing Co., 1981 reprint, 1.463.)

Dr. Hodge then provides two important quotes from the famous Christian historian, Philip Schaff:

It is therefore said, that “the term homoousion, in its strict grammatical sense differs from monoousion or toutoousion, as well as from heteroousion, and signifies not numerical identity, but equality of essence or community of nature among several beings.” “The Nicene Creed,” Dr. Schaff adds, “does not expressly assert the singleness or numerical unity of the divine essence (unless it be in the first article: ‘we believe in one God’), and the main point with the Nicene fathers was to urge against Arianism the strict divinity and essential equality of the Son and Holy Ghost with the Father. (Ibid.)

In the next paragraph, Hodge continues with:

Gieseler goes much further, and denies that the Nicene fathers held the numerical identity of essence in the persons of the Trinity. The Father, Son, and Spirit were the same in substance as having the same nature, or same kind of substance. This he infers was their doctrine not only from the general style of their teaching, and from special declarations, but from the illustrations which they habitually employed. The Father and the Son are the same in substance as among men father and son have the same nature; or as Basil says, Father and Son differ in rank, as do the angels, although they are the same in nature. Gieseler says that the numerical sameness of nature in the three divine persons, was first asserted by Augustine. It was he, according to Gieseler, who first excluded all idea of subordination in the Trinity. “Athanasius and Hilary understood the proposition, ‘There is one God’ of the Father. Basil the Great and the two Gregories understood by the word God a generic idea (Gattungsbegriff), belonging equally to the Father and the Son. (Ibid.)

Though Hodge and Schaff acknowledge that homoousios can be understood in a generic sense, they maintain—contra Gieseler—that it's use in the Nicene Creed should be interpreted in the numeric sense.

Moving from 19th century writers to those of the 20th century, we find the following from the pen of J.N.D. Kelly:

It is reasonable to suppose, pace Eusebius, that a similar meaning, viz. 'of the same nature', was read into the homoousion. But if this is granted, a further question at once arises: are we to understand 'of the same nature' in the 'generic' sense in which Origen, for example, had employed ὁμοούσιος, or are we to take it as having the meaning accepted by later Catholic [i.e. Western] theology, viz. numerical identity of substance? The root word ούσια could signify the kind of substance or stuff common to several individuals of a class, or it could connote an individual thing as such. (Early Christian Doctrine, 2nd ed. 1960, p. 234.)

And from Ivor J. Davidson:

Homoousios was, however, a word with a difficult history. For a start, it was not biblical, which meant that the council [i.e. Nicaea 325] was proposing to talk about the nature of the Godhead in terms that were philosophical or conceptual rather than in language drawn directly from the Scriptures. 

…the outcome of the council was virtually unanimous. All but two of the bishops agreed to sign the creed. The dissenters, Theonas of Marmarica and Secundus of Ptolemais, were both from Libya, where Arius had particularly loyal support. They suffered exile, as did Arius himself. The rest, it seemed, were at one, and Constantine had got his way; the church was united in its opposition to the teaching of Arius [i.e. that the Son was a created being, created ex nihilo, and that there was “a time he was not”].

The reality, however, was for more complex. The apparently all-important homoousios could in fact be understood in a variety of ways. Literally, it meant “same being.” But what was the “sameness” here? To be “the same as” can be “identical to” in a specific sense or “exactly like” in a generic sense. The “being” in question is also vague: a human and animal may both be described as “beings,” but one has on form of “being” (or “nature” or “substance”) and the other another. For staunch enemies of Arius, such as Eustanthius and Marcellus, homoousios meant “one and the same being.” For Eusebius of Caesarea, on the other hand, it meant “exactly like in being”—potentially a very significant difference. Is the Son, the same as God in his being, or is he exactly like God in his being? To Eusebius and many other Greek bishops it seemed better to say that he is like God. (The Baker History of the Church, Vol. 2 – A Public Faith: From Constantine to the Medieval World, AD 312-600, 2005, pp. 35, 36.)

In the selections provided above, our esteemed authors identify four prominent 4th century Church Fathers who interpreted homoousios in the generic sense—Eusebius of Caesarea, Basil of Caesarea, Gregory of Nyssa, and Gregory of Nazianzus. I would now like to introduce a fifth Church Father from the 4th century who affirmed the generic understanding, and also explicitly differentiated between monoousios and homoousios—Athanasius. From his Expositio Fidei we read:

For neither do we hold a Son-Father, as do the Sabellians, calling Him of one but not of the same essence, and thus destroying the existence of the Son. (Statement of Faith, 2.2 - A Select Library of Nicene and Post-Nicene Fathers - Second Series, Vol. 4.84)

The phrase, "calling Him of one but not of the same essence", is a non-literal translation of the Greek, and a bit misleading. The Greek reads as follows:

λέγοντες μονοούσιον καὶ οὐχ ὁμοούσιον  (legontes monoousion kai ouch homoousion)

My translation: saying [he is of] one essence and not [of the] same essence

[Full Greek text of 2.2—οὔτε γὰρ υἱοπάτορα φρονοῦμεν ὡς οἱ Σαβέλλιοι λέγοντες μονοούσιον καὶ οὐχ ὁμοούσιον καὶ ἐν τούτῳ ἀναιροῦντες τὸ εἶναι υἱόν—Migne, PG 25, 204.]

Athanasius identifies the strict numeric understanding of the relationship between the Father and the Son with the Sabellians, contrasting the term monoousion from that of homoousion to drive home his point.

This generic understanding found in Athanasius, Eusebius of Caesarea, Basil of Caesarea, Gregory of Nyssa, and Gregory of Nazianzus (and other Church Fathers), is the dominant understanding of many Eastern Orthodox theologians—theologians who adamantly maintain that it is the only consistent understanding of the use of homoousion in the Nicene Creed and Chalcedonian Definition.

More later, the Lord willing...

Grace and peace,

David