There is a didactic poem, Sopra la composizione della pietra dei Philosophi (On The Composition of the Philosopher's Stone), by Fra Marcantonio Crasselame, which was published in a work significantly entitled La Lumiere sortant par soi-mesme des Tenebres (The Light from Ones Darkness) . As the title shows, this is not the light that was created by the Logos, but a spontaneous, self-begotten light. The poem begins with the creation of the world and declares that the Word created chaos:
At the Omnipotent's first word, shadowy Chaos, formless mass, came from the void.
But who knows how all things were made? Only the "sons of the Art":
O emulous Sons of Divine Hermes, to whom the paternal Art makes Nature visible without any veil, you alone, know how the eternal Hand fashioned earth and Heaven out of shapeless Chaos. Your own great Work clearly shows you that God made Everything in the same manner as the Physical Elixer is produced.
The opus alchymicum recapitulates the secret of creation which began with the incubation of the waters. Mercurius, a living and universal spirit, descends into the earth and mingles with the impure sulphurs, thus becoming fixed:
If I be clearly understood, your unknown Mercury is nothing other than a living innate universal Spirit which, ever agitated in aerial vapour, descends from the Sun to fill the empty Centre of the Earth; whence it later issues forth from the impure Sulphurs and, from volatile, becomes fixed and, having taken form, imparts its form to the radical moisture.
But through his descent Mercurius is made captive and can be freed only by the art:
But where is this golden Mercury, this radical nature, which, dissolved in sulphur and salt, becomes the animated seed of the metals? Ah, he is incarcerated and held so fast that even Nature cannot release him from the harsh prison, unless the Master Art open the way.
It is a spirit of light that descends from the sun (1), a living spirit that lives in all creates as the spirit of wisdom (2), and teachs man the art whereby the "soul enchained in the elements" may be freed. From Mercurius comes the illumination of the adept, and it is through his work that Mercurius is freed from his chains. This Mercurius duplex, who ascends and descends, is the uroboros, by definition an "increatum." It is the snake that begets itself from itself (3). Although the poem takes Mercurius chiefly as a spirit of light, the uroboros is a "subterranean Hermes". Mercurius is a compound of opposites, and the alchemists were primarily concerned with his dark side, the serpent.
(1) "It establishes a twofold motion in Mercurius, one of descend and the other of ascent, and as the former serves to give form to the materials by means of the rays of the sun and of the other stars which by their nature are directed towards lower bodies, and by the action of its vital spirit to awaken the natural fire which is as it were asleep in them, so the movement of ascent serves naturally to purify the bodies." The first descent comes within the story of the Creation and is therefore left out of account by most alchemists. Accordingly, they begin their work with the ascent and complete it with the descent, whose purpose is to reunite the freed soul (the aqua permanens) with the dead (purified) body, thus bringing the filius to birth.
(2) "From it goes forth Splendour, from its light Life, from its movement Spirit."
(3) "It ascends of itself, blackens, descends and whitens, grows and diminishes ... is born, dies, rises again, and thereafter lives forever."