Opinion, Belief, Understanding and Knowledge in Platonic Thought--How Applied to Theology?

Plato makes the following epistemic distinctions in his work, the Republic (509d-510a). These steps go in ascending order: in other words, d) comes before c), etc. I have called these steps--"the epistemic ladder." Others make use of this terminology but sometimes apply it differently at times; see 

https://repository.usfca.edu/cgi/viewcontent.cgi?article=1068&context=phil

https://academic.oup.com/book/32898/chapter/276569490

In any event, here are the four distinctions that Plato makes along with the objects of their episteme:

a) dialectic thought (noesis)-contemplation of the Platonic Forms/Ideas

b) understanding (dianoia)-reflection on or use of mathematics/geometry

c) belief (pistis)-immediately apprehends sensory sensation

d) opinion (eikasia)-rooted in sensory phenomena

How do these distinctions apply to theology? Thomas Aquinas delineates one potential way:

"The truths that we confess concerning God fall under two modes. Some things true of God are beyond all the competence of human reason, as that God is Three and One. Other things there are to which even human reason can attain, as the existence and unity of God, which philosophers have proved to a demonstration under the guidance of the light of natural reason" (Aquinas, SCG 1.3).

To be clear, Aquinas' theology owes more to Aristotle than to Plato, but I'm just showing how the epistemic distinctions of Plato might be applied to theological methods in general. Historically, theologians did make use of Platonic philosophy to shape the contours of their thought: Augustine of Hippo and Justin Martyr are prime examples among the church fathers.

John Philoponus Against Proclus (Lecture Notes)-In Process

The Alexandrian philosopher and theologian John Philoponus (ca. 490-570 CE) constructs a number of arguments against the Neoplatonist theory of Proclus (died ca. 485 CE), a theory which posits that the world is eternal. Conversely, Philoponus contends that the cosmos is neither a deity nor is it eternal (Against Proclus 315.5): later, he gives reasons why he thinks this view is correct. For starters, Philoponus writes:

"That it can be demonstrated from premises with which [our opponents] themselves have provided us that it is impossible for the cosmos to be a god. Including [a demonstration] that a thing which changes in its parts is not unchanging12 [as a whole]."

The brackets and the endnote originally appear in the translation I used.

Besides rejecting Proclus' idea that the universe is divine, Philoponus repudiates the Platonic notion of recalcitrant matter, which Plato insists a demiurge wielded to fashion the material world. This divine craftsman purportedly used absolute and essential Forms to make physical things (315.25). The Platonic Forms are supposed to be Ideals/Ideas; they could be viewed as "concepts," archetypes or essences of the material objects we experience all around us: later thinkers will introduce the distinction, concrete and abstract, to make sense of the Platonic Forms or similar phenomena. But contra Proclus, Philoponus maintains that things come into existence ek mē ontо̄n (316.20):

"That even if it be conceded to be true that enmattered forms either exist or do not exist without generation or perishing, this is itself proof that the cosmos, if it has come to be, has come to be out of things without [prior] existence (ek mē ontо̄n)21 and not out of existing things. And that matter, if it has come to be, must also have come to be out of things without [prior] existence; and therefore the [combination] of the two [must have] as well. And so it may be inferred from this that everything that comes to be comes to be out of absolute non-being."

In addition to refuting the eternal world thesis, he condemns the eugenic program seemingly advocated by Plato in the Republic (page 18): see the fifth book of Respublica.

More condemnation of some content from book five of the Republic follows. See Philoponus, Pages 21-22.

Philoponus criticizes the "subtle lotteries" of Plato, but then returns to making a case for why the cosmos is not a god (pages 23, 27-28). One reason is because the world undergoes spatiotemporal change, a quality which a deity is not supposed to have.

See pages 29-30.

Source Used:  Michael Share (Translator). Philoponus: Against Proclus On the Eternity of the World 9-11. London: Bloomsbury Academic, 2014.