The Philosophy of Natural Magic, by Henry Cornelius Agrippa, L. W. de Laurence ed. [1913], at sacred-texts.com
Platonists say that all inferior bodies are exemplified by the superior Ideas. Now they define an Idea to be a form, above bodies, souls, minds, and to be one, simple, pure, immutable, indivisible, incorporeal and eternal; and that the nature of all Ideas in the first place is in very Goodness itself (i. e.), God, by way of cause; and that they are distinguished amongst themselves by some relative considerations only, lest whatsoever is in the world should be but one thing without any variety, and that they agree in essence, lest God should be a compound substance. In the second place, they place them in the very Intelligible Itself (i. e.), in the Soul of the World, differing the one from the other by absolute forms, so that all the Ideas in God indeed are but one form, but in the Soul of the World they are many. They are placed in the minds of all other things, whether they be joined to the body or separated from the body, by a certain participation, and now by degrees are distinguished more and more. They place them in Nature, as certain small Seed of Forms infused by the Ideas, and lastly they place them in matter, as Shadows. Hereunto may be added, that in the Soul of the World there be as many Seminal Forms of things as Ideas in the mind of God, by which forms she did in the Heavens above the Stars frame to herself shapes also, and stamped upon all these some properties. On these Stars therefore, shapes and properties, all virtues of inferior species, as also their properties do depend; so that every species hath its Celestial Shape, or figure that is suitable to
it, from which also proceeds a wonderful power of operating, which proper gift it receives from its own Idea, through the Seminal Forms of the Soul of the World. For Ideas are not only essential causes of every species, but are also the causes of every virtue, which is in the species; and this is that which many philosophers say, that the properties which are in the nature of things (which virtues, indeed, are the operations of the Ideas) are moved by certain virtues, viz., such as have a certain and sure foundation; not fortuitous, nor casual, but efficacious, powerful and sufficient—doing nothing in vain. Now these Virtues do not err in their actings, but by accident, viz., by reason of the impurity or inequality of the matter: For upon this account there are found things of the same species more or less powerful, according to the purity or indisposition of the matter; for all Celestial Influences may be hindered by the indisposition and insufficiency of the matter. Whence it was a proverb amongst the Platonists, that Celestial Virtues were infused according to the desert or merit of the matter: Which also Virgil makes mention of when he sings:
Wherefore those things in which there is less of the Idea of the matter (i. e.), such things which have a greater resemblance of things separated, have more powerful virtues in operation, being like to the operation of a separated Idea. We see then that the situation and figure of Celestials is the cause of all those excellent Virtues that are in inferior species. *
66:* An Idea of a pure Element, whether the element be of time, space or matter, is an idea that pertains exclusively to such element, correlating with it as perfectly as the idea is perfect. As such idea must be evolved in an intelligent use of such element, so ideas are essential to occult experiment.