Proclus was a late Neoplatonic philosopher, who lived in Athens in the 5th Century A.D. Heir to the long classic tradition his work epitomizes late Neoplatonic thought and was a key link to medieval philosophy. Like Iamblichus he united philosophical rigor with traditional pagan religion and practiced theurgy, literally "god work" which uses ritual and magic for mystic union with the Divine. Proclus saw all things as proceeding from the One and thus despite being separated, all things retain this basic spiritual unity.
In "On the Priestly Art" Proclus explains the spiritual sympanthies and connections that bind together all things in the Cosmos and in particular how particular things are connected through specific chains of spiritual sympathy thus giving a philosophical explanation for the efficacy of both theurgy and magic. Proclus was an important influence on Renaissance mages and philosophers like Marsilio Ficino and Cornelius Agrippa.
Just as lovers systematically leave behind what is fair to sensation and attain the one true source of all that is fair and intelligible, in the same way priests, observing how all things are in all from the sympathy that all visible things have for one another and for the invisible powers, have also framed their priestly knowledge. For they were amazed to see the last in the first and the very first in the last: in heaven they saw earthly things acting causally and in a heavenly manner, in the earth heavenly things in an earthly manner.
So do heliotropes move together with the sun, selenotropes with the moon, moving around to the extent of their ability with the luminaries of the cosmos? All things pray according to their own order and sing hymns, either intellectually or rationally or naturally or sensibly, to heads of entire chains.
And since the heliotrope is also moved toward that to which it readily opens, if anyone hears it striking the air as it moves about, he perceives in the sound that it offers to the king the kind of hymn that a plant can sing.
In the earth, then, it is possible to see suns and moons terrestrially, but in heaven one can also see celestially all the heavenly plants and stones and animals living intellectually. So by observing such things and connecting them to the appropriate heavenly beings, the ancient wise men brought divine powers into the region of mortals, attracting them through likeness. For likeness is sufficient to join beings to one another. If, for example, one first heats up a wick and then holds it under the light of a lamp not far from the flame, he will see it lighted though it be untouched by the flame, and the lighting proceeds upward from below.
By analogy, then, understand the preparatory heating as like the sympathy of lower things for those above: the bringing-near and the proper placement as like the use made in the priestly art of material things, at the right moment and in the appropriate manner: the communication of the fire as like the coming of the divine light to what is capable of sharing it; and the lighting as like the denization of mortal entities and the illumination of what is implicated in matter, which things then are moved toward the others above insofar as they share in the divine seed. like the light of the wick when it is lit.
The lotus also shows that there is sympathy. Before the sun's rays appear, it is closed, but as the sun first rises it is slowly unfolded, and the higher the light goes the more it is expanded, and then it is contracted again as the sun goes down. If men open and close mouths and lips to hymn the sun. how does this differ from the drawing-together and loosening of the lotus petals? For the petals of the lotus take the place of a mouth, and its hymn is a natural one.
But why talk of plants, which have some trace of generative life? One can also see that stones inhale the influences of the luminaries, as we see the sunstone with its golden rays imitating the rays of the sun; and the stone called Bel's eye (which should be called sun's eye. they say) resembling the pupil of the eye and emitting a glittering light from the center of its pupil
And the Moonstone changing in figure and motion along with the moon: and the sun-moonstone, a sort of image of the conjunction of these luminaries. imitating their conjunctions and separations in the heavens.
Thus, all things are full of gods: Things on earth are full of heavenly gods: things in heaven are full of supercelestials: and each chain continues abounding up to its final members. For what is in the One-before-all makes its appearance in all. in which are also communications between souls set beneath one god or another. Thus, consider the multitude of solar animals, such as lions and cocks, which also share in the divine, following their own order. It is amazing how the lesser in might and size among these animals are regarded with fear by those greater in both respects. For they say the lion shrinks from the cock.
The cause of this is not to be grasped from appearances but from intellectual vision and from differences among the causes. In fact, the presence of heliacal symbols is more effective for the cock: it is clear that he perceives the solar orbits and sings a hymn to the luminary as it rises and moves among the other cardinal points. Therefore, some solar angels seem to have forms of this same kind, and though they are formless they appear formed to us held fast in form. Now if one of the solar demons becomes manifest with the shape of a lion, as soon as a cock is presented he becomes invisible, so they say. shrinking away from the signs of greater beings, as many refrain from committing abominable acts when they see likenesses of divine men.
In brief, then, such things as the plants mentioned above follow the orbits of the luminary; others imitate the appearance of its rays (e.g., the palm) or the empyrean substance (e.g.. the laurel) or something else. So it seems that properties sown together in the sun are distributed among the angels, de- mons, souls, animals, plants, and stones that share them. From this evidence of the eyes, the authorities on the priestly art have thus discovered how to gain the favor of powers above, mixing some things together and setting others apart in due order.
They used mixing because they saw that each unmixed thing possesses some property of the god but is not enough to call that god forth. Therefore, by mixing many things they unified the aforemen- tioned influences and made a unity generated from all of them similar to the whole that is prior to them all.
And they often devised composite statues and fumigations, having blended separate signs together into one and having made artificially something embraced essentially by the divine through uni- fication of many powers, the dividing of which makes each one feeble, while mixing raises it up to the idea of the exemplar.
But there are times when one plant or one stone suffices for the work. Flax-leaved daphne is enough for a manifestation: laurel, box-thorn, squill, coral, diamond, or jasper will do for a guardian spirit; but for foreknowledge one needs the heart of a mole and for purification sulfur and salt water. By means of sympathy, then, they draw them near, but by antipathy they drive them away, using sulfur and bitumen for purification, perhaps, or an aspersion of sea water. For sulfur purifies by the sharpness of its scent, sea water because it shares in the empyrean power. For consecrations and other divine services they search out appropriate animals as well as other things.
Beginning with these things and others like them, they gained knowledge of the demonic powers, how closely connected they are in substance to natural and corporeal energy, and through these very substances they achieved association with the [daimons], from whom they returned forthwith to actual works of the gods, learning some things from the [gods], for other things being moved by themselves toward accurate consid- eration of the appropriate symbols. Thence, leaving nature and natural ener- gies below, they had dealings with the primary and divine powers.
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