Astrological images: from the Picatrix to the second book

Among the most debated themes of Renaissance magic is that of astrological images. The name referred to figures engraved on metals or stones, or painted, representing planets, zodiac signs, decans or constellations, which, according to tradition, if made at a favourable celestial moment, would receive the virtues of the stars. The second book of the De occulta philosophia devotes a series of chapters to this subject, gathering descriptions handed down by ancient and above all Arabic sources.

The Arabic sources

The doctrine of images had developed largely in the medieval Islamic world. The most important text was the Ghayat al-hakim, «The Aim of the Sage», a vast Arabic treatise on astral magic probably composed in the tenth or eleventh century and translated into Castilian and then into Latin at the court of Alfonso X of Castile, in the thirteenth century, under the title Picatrix. The book described hundreds of planetary and zodiacal images, set within a cosmology of Hermetic and Neoplatonic inspiration.

Equally well known was the De imaginibus attributed to Thabit ibn Qurra, a mathematician and astronomer active in Baghdad in the ninth century, which explained how images could receive celestial influences. Agrippa draws on these texts and on other writings attributed to Hermes, to Ptolemy and to various Arabic authors, reporting their descriptions with few changes and without always indicating where they came from.

The theologians' debate

Images raised a delicate problem. Could they act by natural virtue, thanks to the rays of the stars, or did their effect depend on the intervention of demons? Thomas Aquinas, in the Summa contra gentiles, had argued that figures as such have no natural power, and that if they produce effects these must be attributed to separate intelligences, and thus to demons. The Speculum astronomiae, attributed to Albertus Magnus, had attempted a distinction between licit and illicit images.

Ficino, in the De vita of 1489, had approached the question cautiously, reporting the opinions of the ancients without fully committing himself. Agrippa is less cautious: in the De occulta philosophia images become an integral part of celestial magic, because the figure, like number, is for him the bearer of a form corresponding to the forms of the heavens.

Images and figurative art

The descriptions of astrological images did not remain shut up in books of magic. In the Hall of the Months of the Palazzo Schifanoia in Ferrara, painted around 1470, appear the figures of the thirty-six decans, which the art historian Aby Warburg, in a famous study presented in 1912, traced back to the Introductorium maius of the Persian astrologer Abu Ma'shar, through a long chain of translations. These images show how astral iconography circulated in the Italian courts.

Agrippa's second book gathers many similar images: the figure of Saturn as an old man with a scythe, that of Jupiter as an enthroned king, that of Mars as an armed warrior, alongside stranger figures derived from the decans and the lunar mansions. They are iconographic descriptions more than instructions, and today they are of interest above all for what they reveal about the imagination of the Renaissance.

The theme of images shows how much Agrippa's magical thought owed to the Arabic world. Through the Latin translations of the Middle Ages, ideas born in Baghdad, in Harran or in al-Andalus reached the printing houses of Cologne, intertwining with Florentine Platonism and with the disputes of the theologians. The history of astrological images is therefore also a history of translations.