...the Catechism... states: All creatures bear a certain resemblance to God
2. That God's essence bears a resemblance to creatures.Actually, St. Thomas flatly rejects the idea that God resembles creatures.
I have to agree -Sandinopolous's wording was technically amiss at that point. Aquinas thought it true that creatures resemble God, but improper to say God resembles creatures.
I also agree with the Via Negativa approach Papist mentioned, which Aquinas derived from the pseudo-Dionysian corpus. No real conflict between Aquinas and EO at that point -Aquinas is not by any means wrong about everything.
Turning back to the OP, it might be worthwhile to cite earlier RC writers who regarded East and West as opposed on related points, before the more modern ecumenical modality of insisting "we are really the same except for different terminology" came into fashion.
The Catholic Encyclopedia describes the Orthodox essence/energy distinction as "fundamentally opposed to" Scholasticism on the basis of divine simplicity:
"The other element of fourteenth-century Hesychasm was the famous real distinction between essence and attributes (specifically one attribute — energy) in God. This theory, fundamentally opposed to the whole conception of God in the Western Scholastic system, had also been prepared by Eastern Fathers and theologians...
The Greek Fathers (after Clement of Alexandria mostly Platonists) had a tendency in the same way to distinguish between God's unapproachable essence and His action, energy, operation on creatures. God Himself transcends all things. He is absolute, unknown, infinite above everything; no eye can see, no mind conceive Him. What we can know and attain is His action. The foundation of a real distinction between the unapproachable essence (ousia) and the approachable energy (energeia) is thus laid. For this system, too, the quotations made by Hesychasts from Athanasius, Basil, Gregory, especially from Pseudo-Dionysius, supply enough examples. The Hesychasts were fond of illustrating their distinction between God's essence and energy (light) by comparing them to the sun, whose rays are really distinct from its globe, although there is only one sun. It is to be noted that the philosophic opponents of Hesychasm always borrow their weapons from St. Thomas Aquinas and the Western Schoolmen. They argue, quite in terms of Latin Aristotelean philosophy, that God is simple; except for the Trinity there can be no distinctions in an actus purus. This distinct energy, uncreated light that is not the essence of God, would be a kind of demiurge, something neither God nor creature; or there would be two Gods, an essence and an energy. http://www.newadvent.org/cathen/07301a.htm
The same Catholic Encyclopedia article references St. Gregory Palamas's opposition to the equation of God's essence and attributes, which is part of divine simplicity as conceived in scholasticism:
Gregory Palamas (d. about 1360; Krumbacher, op. cit., 103-105) was a monk at Athos, then from 1349 Bishop of Thessalonica. He wrote no less than sixty works in defence of Hesychasm, one especially against the Scholastic identification of God's essence and attributes. He found fifty heresies in his opponents. He was also vehemently anti-Latin, wrote a refutation of John Beccus's latinizing work, and did his duty by Orthodoxy in supplying the usual treatise against the double procession of the Holy Ghost. Naturally his opponents call him a ditheist, while he considers them Arians, Sabellians, and Epicureans... Gregory Akindynos, a friend and contemporary of Barlaam, also a monk, wrote a work against the Hesychasts "Peri ousias kai energeias," in six books, of which the first two are nothing but translations from St. Thomas's "Summa contra Gentes".
Also Hesychasm is dismissed as a form of autosuggestion; this may be influenced by the perception of doctrinal incompatibility of East and West in that article.
"After Isaias, John XIV (John Aprenus, 1334-47) had become patriarch. Barlaam demanded of him a synod to settle the question. For a time the patriarch refused to take the matter so seriously; eventually, since the quarrel became more and more bitter, in 1341 the first synod of the Hesychast question was summoned at Constantinople. The emperor (Andronicus III) presided. This first synod considered only two questions; (1) Whether the light of Thabor (that of the Transfiguration) was created or not; (2) a certain prayer used by Hesychasts, stated by Barlaam to contain ditheism. The enormous influence of the monks at Court and the want of energy of the patriarch (who was in his heart on Barlaam's side) made this first synod a victory for Hesychasm. In both points the monks and their theory were approved, and Barlaam was forced to withdraw his accusations. Soon afterwards he left Constantinople forever; his cause was taken up by Gregory Akindynos. The emperor died a few days after the synod. John VI, Cantacuzenus (1341-1355), who gradually usurped the imperial power, first as rival, then as fellow-emperor, of Andronicus's son John V, Palæologus (1341-76), was always a friend of Palamas and the Hesychast monks. The second Hesychast synod under Cantacuzenus, but without the patriarch, condemned Akindynos and introduced a new element by representing him and all its opponents as latinizers who were trying to destroy Orthodoxy... Hesychasm had become so much identified with the cause of the Orthodox Church against the Latins that the other side never succeeded in ousting it. On 2 February, 1347, the fourth Hesychast synod was held. It deposed the patriarch, John XIV, and excommunicated Akindynos. Isidore Buchiras, who had been excommunicated by the third synod, was now made patriarch (Isidore I, 1347-1349). In the same year (1347) the Barlaamites held the fifth synod, refusing to acknowledge Isidore and excommunicating Palamas. From this time Nicephorus Gregoras becomes the chief opponent of Hesychasm. Isidore I died in 1349: the Hesychasts replaced him by one of their monks, Callistus I (1350-1354). In 1351 the sixth synod met in the Blachernæ palace under Cantacuzenus. Gregoras defended his views boldly and skillfully, but again the Hesychasts had it all their own way, deposed Barlaamite bishops, and used violence against their own opponents. In this synod six questions about God's essence and attributes were answered, all in the Hesychast sense, while Palamas was declared to be without any doubt orthodox and unimpeachable. The synod finally published, in defence of Palamas and his views, a decree (Tomos) which eventually was looked upon as an authentic declaration of the Orthodox Church. From this time Hesychasm may be said to have defeated all opposition... After the deposition of Cantacuzenus, the Barlaamites held an anti-Hesychast synod at Ephesus; but the patriarchs of Constantinople and the great mass of the people had by now become too firmly persuaded that the cause of Hesychasm was that of Orthodoxy. To oppose it was to incur the guilt of latinizing; so even Cantacuzenus's fall was not enough to turn the scale. Hesychasm from this time is always triumphant. About 1360 Palamas died. In 1368 the seventh Synod of Constantinople (concerning this matter) under the Patriarch Philotheus (1364-1376: Callistus's successor) excommunicated the Barlaamite monk Prochorus Cydonius, confirmed the "Tomus" of 1351 as a "Faultless Canon of the true faith of Christians", and canonized Palamas as a Father and Doctor of the Church. So by the end of the fourteenth century Hesychasm had become a dogma of the Orthodox Church. It is so still ...the Orthodox still maintain the Tomus of 1351 as binding; the real distinction between God's essence and operation remains one more principle, though it is rarely insisted on now, in which the Orthodox differ from Catholics.
The Catholic Encyclopedia article concludes by reaffirming the fundamental opposition of Hesychasm and scholastic theology: ...Latin theology on the whole was too deeply impregnated with the Aristotelean Scholastic system to tolerate a theory that opposed its very foundation. That all created beings are composed of actus and potentia, that God alone is actus purus, simple as He is infinite — this is the root of all Scholastic natural theology.