Photios may object to my posting his reply (as opposed to a polished paper) in a comment thread on Dr. L’s site, but he summarizes quite nicely I think the Orthodox understanding of Person and essence:
Are you clear, from an Orthodox perspective, that there is no divine essence abstraced from person? That the divine nature is the content of the person and that it is concrete only in enhypostatization? That is, nature only has existence in a person. To continue on this line, what various scholastic authors have setup in abstracting a concept of a divine essence prior to consideration of persons, in which it (i.e. the divine essence) only truly subsists, is (again from an Orthodox perspective) no divine essence at all. In that respect, I would agree with many of the heavy-handed a-theist type arguments that are leveled at the “proofs” for the existence of God.
Having said that, I believe it is misleading to construe Palamas’ view of divine essence as a mere universal, “or as an abstraction from reality,” since Palamas would never analyze a concept of divine essence apart from Persons, and vice versa, which is why Lossky says, “There is neither an impersonal substance nor non-consubstantial persons. The one nature and the three hypostases are presented simultaneously to our understanding, with neither prior to the other. The origin of the hypostases is not impersonal, since it is referred to the person of the Father; but it is unthinkable apart from their common possession of the same essence, the “divinity in division undivided.” St. Gregory of Nazianzus, Or. 31, 14; P.G. 36, col. 148D. Otherwise we should have Three Divine Individuals, Three Gods bound together by an abstract idea of Godhead. On the other hand, since consubstantiality is the non-hypostatic identity of the Three, in that they have (or rather are) a common essence, the unity of the three hypostases is inconceivable apart from the monarchy of the Father, who is the principle of the common possession of the same one essence.”