Gregory of Nyssa's take on Cave Theory

St. Gregory of Nyssa calls the spiritual life a journey from light to darkness, and darkness to light. But it is “a transition from a light which is darkness to a darkness which is light.”

He goes onto say the “the mind must detach itself from sensible appearances and seek God in those invisible realities which the intellect alone can apprehend.” “This darkening of the senses is like a cloud in which the soul becomes accustomed to traveling blind, without relying on the appearances of changing things or on the emotional import of experience in its judgments of truth and falsity, of good and evil.”

These are the words of Thomas Merton, from his book “The Ascent to Truth”. In pondering the concept of finding truth in darkness (the Cave) I have found these quotes interesting; while not necessarily buying into them completely. My question to put forth here is, what does seeking God in the “cloud” look like? How does one discern the difference between false light and true light, and false darkness (which is truth) and darkness (which is falsity). Merton speaks of “traveling blind”, but what does that really mean? It is obvious, in his book, that he is not speaking of ignorance, but some sort of letting go of pre-conceived notions to understand Truth. This stuff freaks me out, but also leaves me with a desire to understand these concepts better. Hence a posting of questions to see what you think. One last quote referring to the light found in the cloud of darkness.
“But this darkness is pure light because it is the infinite Light of God Himself. And the mere fact that His light is infinite means that it is darkness to our finite minds.”
Something about that last line hits me, but I’m not sure yet what I think. How ‘bout you?