“St. Bonaventura, in his doctrine of ‘signatura rerum’, interprets the entire visible world as the symbol of the invisible world. For him, the visible world is only another Holy Scripture, another revelation alongside that which is contained in the Holy Scripture properly said:
“And it thus appears that the entire world is like a single mirror full of lights presenting the divine wisdom, or as charcoal emitting light.”
~ Meditations on the Tarot, Letter 1, “The Magician” (17)
The context for the above quotation is Our Anonymous Author’s discussion of the method of analogy as it pertains to philosophy and theology (citing, along the way, papal proclamations in 1588 and 1879 which describe St. Thomas Aquinas and St. Bonaventure as “two olive trees and two chandeliers shining in the house of God”).
No doubt many (if not most) of us have read at least a bit of Aquinas, right? But how many of us are at all familiar with St. Bonaventure? While a google search turns up a plethora of resources, perhaps these two will be at least minimally sufficient for a first introduction:
The Cosmic Exemplarism of Bonaventure
Bowman, Leonard J. The Journal of Religion, Vol. 55, No. 2 (Apr., 1975), pp. 181-198.
Bonaventure on Creation: A Ressourcement for the Modern World
Kimball, Kasey. Crux, 51 no 4 (Winter 2015), 15-21.
The Kimball article is by a graduate student in theology who is, in part, addressing
ecological concerns (bringing Martin Heidegger and Martin Buber into the mix). The Bowman piece is strict exposition and seems to captures an essential element of authentic Christian Platonism in these paragraphs:
As Bonaventure makes clear– along with Plotinus —it is a HUGE mistake to imagine the intelligible realm of Platonic ideas to be a mere aggregate of eternal abstractions. Quite the contrary. Indeed, Nous for Plotinus is the locus of our truth and being — the living and powerful essence of our existence which is, itself, pure act. Moreover, we find that in Nous, which invites comparison with the Divine Intelligence of the Christian Logos, eternity and mutual inclusiveness replace time, space, and separation (Enneads V.9.10). So while, on one level– that of the empirical ego –we may be lost in time and space (consumed by our very material concerns), Plotinus is quite clear that our higher part remains–we need only recollect our race and worth (cf. IV.8.8, V.1.1). 
To know this higher aspect of ourselves is to know eternal life— authentic Spiritual Life –which is our true vocation (having been chosen/created in Christ before the foundation of the world in the beginning with God). But to realize this also requires the courage to be–the courage to be that which we ARE in Christ, Here & NOW. Thus the exhortation: Take up your cross, the kingdom of heaven is at hand . . .
“The Now is no mere nodal point between the past and the future. It is the seat and region of the Divine Presence itself…. The Now contains all that is needed for the absolute satisfaction of our deepest cravings…. In the Now we are at home at last.”
~ Thomas Kelly, “A Testament of Devotion”
Note: Below is an additional except from the Bowman article:
Christian Meditations on the Tarot www.cmott.net 