I have been looking into Masonic/Rosicrucian motifs in Pale Fire. Both secret societies call themselves "gradual," and have systems of "graded" "degrees" of initiation and progression towards spiritual knowledge/perfection. Rather like the well-known textbook on prosody, Gradus ad Parnassus, which are "steps" to achieving the heights of poetry.
These, of course, are words that are associated with PF's Gradus. But Gradus is hardly spiritually perfected, in fact, degraded. Gradus, however, like Shade and Kinbote, is likewise on a quest - to kill Kinbote. If we can see that the three characters are archetypes in Prof. Botkin's mind, and that it is really Prof. Botkin who is making "steps" towards enlightenment, then it is Gradus, the Shadow, who causes the irruption in the glass factory of Botkin's unconscious which instigates the quest to "kill" the Ego (Kinbote), through first "killing" the ego-ideal Persona, Shade. Then, Gradus realizes he was never really any good, no longer needed and kills himself. That is, the Shadow (unconscious) has become self-conscious and cannot continue as a Shadow. This is the "Hero's Journey" (Jung's path of individuation) quest in brief. Masonic and Rosicrucian societies are founded on alchemy, hermeticism, Kaballah systems of magical transmutation of the soul of the "tri-part" man.
SO... I just found out that the Rosicrucians teach that their "gradual" "degrees" are aimed at the Holy Grail, which comes from the word "gradalis."
.--The 'Just Man made Perfect' is the Alchemist (or rather, Rosicrucian) who, having found the Philosophers’ Stone (San Graal, or Holy Grail, or 'Sang Reale' or 'Holy Rapture' or Magic Birth into the Celestial Fire, or flame of Self-Extinguishment, or of 'Ecstasy'), becomes immortal (and disappears, or 'dies' to the world).
Here is a wikipedia description of Grail etymology (my emphasis in bold):
The most commonly accepted etymology derives it from Latin gradalis or gradale via an earlier form, cratalis, a derivative of crater or cratus, which was, in turn, borrowed from Ancient Greek krater (κρᾱτήρ, a large wine-mixing vessel). Alternative suggestions include a derivative of cratis, a name for a type of woven basket that came to refer to a dish, or a derivative of Latin gradus meaning "'by degree', 'by stages', applied to a dish brought to the table in different stages or services during a meal".
Remember the "krater" in the castle tunnel? Alchemists sometimes called their vessel a krater. Another word they employed was situla. Remember Kinbote's situla in the castle closet? Kinbote has had his little situla pail since childhood, which he filled with the precious things of his childhood: shiny stones and seashells, just as children gather special memories. As a little boy, King Charles brought these "treasures" for the approval of his father, King Alfin, to admire. Although King Alfin was actually a complete air-head, like all fathers to little boys he was god-like; thus the "conchologist" Kinbote later refers to (as well as to himself):
To return to the King: take for instance the question of personal culture. How often is it that kings engage in some special research? ConchoJogists among them can be counted on the fingers of one maimed hand.
The little situla, when Kinbote finds it, no longer is filled with pebbles and shells; they have been "transmuted to a precious blue diamond. In esoteric circles, the brilliant indigo circle with a diamond-like star inside is seen by the 3rd eye as one meditates and grows in consciousness. I believe this is the blue diamond in the situla, and is the real "talisman" he takes with him on his journey. It shows up after his trek as the "pebble" he finds in his shoe (shoes being a PF motif for the soul/sole). The copy of Timon of Athens, although he takes that too, I believe is a red herring.