Doctrine of Signatures

Giambattista della Porta was a popular scientist and magician in sixteenth-century Italy. Born into Naples aristocracy, della Porta established a Wunderkammer of natural history specimens and used it to produce his first herbal, Magiæ Naturalis, while in his early twenties. The volume contains twenty books of magical “cures” ranging from the “beautification” of women to the production of counterfeit gemstones and invisible ink.

For two decades following his first major publication della Porta traveled the continent to establish connections with successful scientists of the period. He published extensively on the cultivation of fruit trees, the “science” of physiognomy, and the philosopher’s stone. In 1588, della Porta published his second herbal, Phytognomonica, from which the above engraving is taken. The volume adheres to the ‘doctrine of signatures,’ a system of folk medicine dating to the Middle Ages and named by the German mystic Jakob Boehme in 1621. The doctrine posited that natural objects resembling parts of the body could treat diseases that arise there. This “imitative natural magic” was the “signature” left on nature by God. Thus, the Phytognomonica claims that plants with a milky sap lead to the production of milk, and plants shaped like scorpions can be used to treat a scorpion sting. The engraving above shows the purported resemblance between certain plants and the horns of an elk, ox, unicorn, and ram.