Coincidence of the once disparate

Is it because one is old that new elements and others remembered from the past seem to coincide? Years ago, in the 1970s, Sister M.C., then novice mistress, handed me a lovely Thames and Hudson publication on The Tree of Life. On the cover, and again inside, was a 15th century full-page painting from a Ms, German or Swiss, I think, of Adam and Eve and the Serpent on the Tree in the Garden. I might meditate on it if I wished. It was no common image; everything in it, though nominally natural, was potently significant. Eve was certainly Mary and the Church. The Serpent was neither innocent nor ugly, and it had a feminine head (reminding me now of the Glykon serpent found at Tomis or the Agathos Daimon of Alexandria). But I can't remember all the details, nor can I find my notebook in which I wrote about it, and what I wrote then I might dislike now, if I considered it personally. Even then, however, I took Sister's lending it to me as a way into the devotional mentality that had sponsored and produced it. The text of the book was Jungian, and already I was in no mood to play Bill Moyers to Joseph Campbell, but the picture was theological, to the nth degree. I had associated this kind of thought with the continuum from Boethius through Aquinus and especially in the beautiful Latin of the Victorines, some of which I had read in the year before I entered the convent, and with Chartres.
I was surprised, therefore, to discover it intact and so intense in a 15th-century Ms.
Then yesterday my lifelong friend, N.S., sent me her completed paper on Josquin's Illibata Dei in its theological and political context, in the ecclesiastical conflicts of the century following the Council of Constance. It isn't published yet, so I can't cite it, but the same learned intensity that I had discovered in the Ms painting is fully and beautifully set forth in this paper. As I was taught (and everyone is taught by a certain faculty at a certain juncture of time and academic geography), the art of the middle ages was theological and that of the 15th century was preponderantly secular, the artists more formally concerned, and none of them much engaged, intellectually (except for Albrecht Dürer), with theological philosophy. Of course, that wasn't true, but perhaps my mentors permitted one's having that impression. And I do not recall from the Norton Introduction to the History of Music reading anything about the composers as scholarly propagandists, so to speak. I suppose I thought of them as resembling the popular accounts of the lives of Romantic composers.
Once again, as several times before in my life, history leapt to life, life as strenuous as today's news. One consequence was to set me to searching for at least a draft of my explication of that Adam and Eve picture. I didn't find it, but I found a stack of notebooks of meditations and the like from 1974 to 1981, which I had put away but not destroyed, some of them as tortuous in their struggle to think properly, to make myself believe what I wrote, as anything in Edmund Gosse's Father and Son. Yes, and that was why I had read Gosse so eagerly, for the earnest struggle and its dreadful effect on one's mentality. It wasn't as if anyone was asking me to be like the Plymouth Brethren, but that I was striving so hard to come to terms with a decision that I ought not to have made, that was made out of several kinds of cowardice in the face of life. Abandonment is not abnegation, whether abnegation is itself good or bad. And I can assure the author of the excellent blog whom my mentioning Sir Thomas Browne led to his leaving me a comment (and to my enjoying his blog immensely) that I had no idea that Gosse had written on Browne, and I can't imagine what his biography of Browne might be like.
But Browne, of course, brings us to further religious and political troubles, to the middle of the 17th century and to the everlasting question, whether a spiritual life implies any religious adherence, specifically adherence to a religion of the Book. Daoism, for instance, and even the heart of Buddhism are not theistic, and Lucretius and Plotinus, finally Boethius (naming only the most famous) are spiritual philosophers. So far as there being any contradiction between the intense spiritual content of Shostakovich's music and his professed atheism, I am inclined to think that the purest spirituality is often either atheistic or agnostic. Enthused spirituality, if I may name St. Teresa as such, is less intellectual and less pure, it seems to me. That of the mature Shostakovich, not to mention Beethoven in his late quartets or Brahms or Webern (choosing my favorites), is the real thing—or, should I say, the actual thing? Browne's Religio Medici reminds me, in a limited sense, of Bishop Gore of Oxford who quietly admitted, in a single sentence, that it was at such times as he could see the existence of a personal god that "all the rest followed". I'd cite the book literally if I had it at hand.
The crux of all this, from the first philosophers who tried to grapple with the interface of deity and reason through all the remarkable history of the forced marriage of sensory experience to mental experience, of the philosophy of the five senses to that of dreams and visions and glimpses of the beyond, is perhaps the essence of intellectual history. And aesthetics? Bremond's Prière et Poésie?

The picture book with the Adam and Eve was that by Roger Cook. The printings currently accessible of Cook's title have a different front cover and an inferior reproduction (pl. 44) of the Tree of Life / of the Knowledge of Good and Evil picture reproduced in it. It is, however, evidently the same: Berthold Furtmeyer, from the Missal of the Archbishop of Salzburg, AD 1481. Nearest to it iconographically is Hugo van der Goes's painting, which, however, is more straightforward (and it has the female headed serpent).
The basic study for Chartres is The Sculptural Programs of Chartres Cathedral by Adolf Katzenellenbogen.
Panofsky's Renaissance and Renascences and E. R. Curtius's European Literature and the Latin Middle Ages, inter alia, also influenced my thought.
There are of course also primary sources. And Abbé Bremond's essay, also in English, dated from 1918.