Commentary on the First and Second Chapters of the Thirtieth Book of the Natural History of Gaius Plinius Secundus

Natural Magic, therefore, is nothing other than Physics and Astrology: by comparing these, it can be gathered that no one is a Magus unless he is marked by these three disciplines: for by comprehending Physics and Metaphysics, the Magi implicitly include Astrology. For physical erudition declares the qualities of things, which almost entirely overturn all the properties of any Entity whatsoever. Furthermore, unless one is a master of Metaphysics, one will not be able to understand Magic: because he will not easily grasp the aspects and figures of the stars, nor from where hidden properties and virtue depend. For the Magi claim there is no magical work that is not supported by the aid of these sciences. Moreover, it will not be unhelpful to have noted what would be pleasurable for the Reader and useful to have read: For those most skilled in the nature of things claim that there are natural things which are called Elemental, such as heating, drying, moistening, and things of that kind, and that they are called primary Qualities. Furthermore, there are gifts in natural things beyond the primary qualities, such as the virtue of maturing, resolving, hardening, expelling, and retaining. There are, besides, other virtues in things that are not of any Element, such as fleeing poison: attracting iron, like the Magnet: putting Demons to flight, like the Diamond original: "Adamas". According to some, such virtue is not elemental, yet it has an abstruse and latent effect: for these virtues, because they are very much (if Latinity permits the use of this word) formal, therefore they can do much with little matter. Elemental virtue, however, because it is material, demands much matter to do much. These virtues are called occult properties, because their causes are abstruse and latent. Hence, with a more fortunate investigation of experience, the greatest part of philosophers has acquired the virtues of these things: For by this more occult force, the Ostrich original: "Strutiocamelus" digests iron without discrimination, and it is converted into the substance of nourishment. Thus the little fish Echeneis original: "Echineis" holds back ships: thus the Basilisk kills by sight alone, and many things of that kind which, sparing the ambiguities of words, I omit. Furthermore, it should be noted that the Platonists left it written that all inferior things are