Kevin Edgecomb has a post from the homilies of St Isaac of Syria. I worry about the cerebralization of Spirit in these levels of knowledge that are considered given from the analytical point of view of his century (He died c 700 according to Wikipedia - I have little reason to doubt this tidbit.)
Suppose all I had from him was this Homily 52 on knowledge and Kevin's good opinion (which I trust), what would I make of his teaching on knowledge?
Three levels - 1 bad, 2 and 3 good? - No he is more subtle than that but there is a danger to the reading of level 1 as 'bad' which includes
wealth, vainglory, honour, adornment, rest of the body, special means to guard the body’s nature from adversities, assiduity in rational wisdom, such as is suitable for the governance of the world and which gushes forth the novelties of inventions, the arts, sciences, doctrines, and all other things which crown the body in this visible world.
But he adds:
Among the properties of this knowledge belong those that are opposed to faith, which we have stated and enumerated above. This is called shallow knowledge, for it is naked of all concern for God. And because it is dominated by the body, it introduces into the mind an irrational impotence, and its concern is totally for this world.
So knowledge level 1 is not all bad. But it would be easy to miss this in the rest of the homily.
knowledge [that] makes straight the pathways in the heart which lead to faith, wherewith we gather supplies for our journey to the true age.And of the third degree:
I don't think he has said much here for all his words. What knowledge is that comes by faith - if indeed it can be separated by stage (and here Isaac does not insist on his three stages) - is not so much our knowledge of mysteries - though it is that, but rather the Mystery's knowledge of us. May it be that he will not say - Depart from me for I never knew you.
Hear now how knowledge becomes more refined, acquires that which is of the Spirit, and comes to resemble the life of the unseen hosts which perform their liturgy not by the palpable activity of works, but through the activity accomplished in the intellect’s meditation. ... faith itself swallows up knowledge, converts it, and begets it anew, so that it becomes wholly and completely spirit.