There are three levels of interpretation: the physical-material (literal), the psychological (moral) and the spiritual (allegorical). We could name the physical level, exoteric, the psychological, mesoteric and the spiritual, esoteric. With the term exoteric, we mean that it refers to things outside us. The term mesoteric indicates an intermediate level of our being which is not exoteric but neither constitutes our innermost depth. The term esoteric refers to our very depth, to our very selves.
This book has been published in English translation from Theosis Books:
You can watch a short presentation from Theodore J. Nottingham here:
It has been titled “Divinization: The Hidden Teaching within Divine Wisdom” and you can purchase it from Amazon: