In the Renaissance the word "magic" did not necessarily mean dealings with spirits. There was also a natural magic, understood as knowledge of the hidden virtues of things and the ability to produce marvellous effects using only the forces of nature. Its most famous representative was a Neapolitan nobleman, Giambattista Della Porta, whose Magia naturalis was one of the most widely read books of its century.
A curious gentleman
Della Porta was born in 1535 into a well-to-do family, between Vico Equense and Naples, and was educated at home by private tutors together with his brothers, with whom he shared a passion for experiments and collections. He never regularly attended a university nor practised a profession: he was an independent researcher, a scholar who devoted his life to observing, experimenting and writing.
The Magia naturalis
The first edition of the Magiae naturalis appeared in Naples in 1558, in four books. In 1589 Della Porta published a second, greatly enlarged version in twenty books, which is the best known.
In the preface he clearly distinguishes two kinds of magic: one, which he rejects, based on impure spirits; the other, natural, which is "the consummation of natural philosophy". The natural magician, he writes, is one who knows the sympathies and antipathies between things and can bring them together so as to produce surprising effects.
The content of the work is a true catalogue of secrets:
| Field | Examples of topics covered |
|---|---|
| Botany and agriculture | Grafting, seedless fruit, new plant varieties |
| Distillation | Extraction of essences and perfumes |
| Optics | Mirrors, lenses, the camera obscura with a lens |
| Magnetism | Properties of the lodestone |
| Cookery and cosmetics | Preserving food, preparations for the body |
| Cryptography and tricks | Invisible writing, illusions and conjuring |
The description of the camera obscura, a dark room in which a hole fitted with a lens projects images of the outside onto the wall, is one of the most quoted passages. Della Porta did not invent it, but he described it so effectively that its use spread among painters and the curious.
The Academy of Secrets and the Inquisition
In his house in Naples Della Porta gathered a group of scholars that took the name Academy of Secrets: to be admitted one had to bring the discovery of a natural secret not yet known. It was one of the first European societies devoted to research into nature.
His activity, however, attracted the attention of the Inquisition. Around 1578 Della Porta was summoned to Rome; the academy was closed and he was asked to abandon illicit arts. In the following years some of his works were subjected to scrutiny and the publication of his physiognomy met with obstacles. Della Porta remained an observant Catholic and suffered no serious condemnation, but from then on he was very cautious.
Physiognomy, optics and theatre
His other works show the range of his interests:
- De furtivis literarum notis (1563), one of the most important sixteenth-century treatises on cryptography;
- De humana physiognomonia (1586), in which he compares human faces with those of animals to deduce character, with illustrations that became famous;
- Phytognomonica (1588), which applies the same method to plants, seeking in their shape the signs of their properties;
- De refractione (1593), on optics and vision;
- numerous comedies, including La fantesca and La sorella, which made him one of the most prolific playwrights of his time.
Della Porta's physiognomy has no scientific value today, but it enjoyed a long fortune in art and literature up to the nineteenth century.
The Lincei and the telescope
In 1610 Della Porta, by then elderly, was received into the Accademia dei Lincei founded by Federico Cesi, of which Galileo would also be a member. When Galileo presented the telescope, Della Porta claimed to have described its principle in his works. The claim is debated: his texts speak of combinations of lenses, but not of an instrument built and used for astronomy. He died in Naples in 1615.
In short
- Giambattista Della Porta (1535-1615) was a Neapolitan scholar and the leading theorist of natural magic.
- The Magia naturalis (1558, then 1589 in twenty books) collects secrets of optics, botany, distillation and magnetism.
- He founded the Academy of Secrets, closed after the Inquisition intervened.
- He was also a cryptographer, a writer on physiognomy, a playwright and a member of the Lincei.
