The problems are these:
1. That religious knowledge is divided into two categories – “natural” theology and revealed theology.
2. That God’s essence bears a resemblance to creatures.
3. That we reason up from creatures via “analogia entis” to know something of God’s essence.
4. God created things in the world after archetypes of things pre-existing in His essence.
5. That nature and Person are identical in God.
6. That essence and energy/action are the same in God, as well as all attributes being the same. This “god” is actus purus – pure act.
7. That the meaning of theosis or salvation is being raised to a higher level of created grace.
8. That the eschaton is an intellectual vision of the essence of God, as well as being a bizarre lake of lava where demons throw you in and out and evil and sin continue in eternal opposition to God (dualism).
These are the awful ideas of scholasticism. It’s NOT bad because it uses philosophy and logic. If that were true, then Nyssa, Maximus, Basil, Theodore, Athanasius, the two Cyrils, John of Damascus, and all Eastern Fathers are all “scholastics.” And I’ve read every one of them at length. They were classically educated. But that’s not what the criticism is. That’s what unknowing Orthodox think the criticism is (as I thought for a long time and it partly kept me out of Orthodoxy, since it was hypocritical).
Scholasticism is the train of schoolmen who follow in the footsteps of Augustine and his philosophical assumptions – it’s the three “As” – Anselm, Aquinas and Augustine. It’s Duns Scotus and Peter Lombard – all of whom are in varying degrees using the above assumptions.