Subtlety

Daily Draw: The Pierpont Morgan Visconti Sforza Tarocchi Deck, Knave of Swords

This Knave's sword points downwards indicating a person capable of discerning and uncovering the unknown or obscure. The word occult has acquired different connotations now compared with when it emerged in the fifteenth century and simply meant 'covered-over' from the verb occulere 'conceal'. 

In the sixteenth century it was in no way personally inconsistent to be at once a university qualified medical doctor and an occult scientist. That contemporaries did not draw those lines so sharply is evident in the career and writings of Renaissance polymath Girolamo Cardano. 

Until recently Cardano was best known autobiographer, producer of early encyclopaedias, mathematician and astrologer with interests including history, music, dreams and physiognomy.

However his prime purpose was to propose an innovative philosophy of nature based on his concept of subtlety. Subtlety was his way of conceptualising a special characteristic inherent in things which was difficult to grasp by the senses or the intellect. It could be discerned in all manner of difficult and obscure things both natural and man-made. Thus understanding subtlety was the key to knowledge of all in nature and the arts. The kinds of knowledges he had in mind ranged from mechanical principles at work in technological devices to the magus's insights into occult forces in nature. 

Cardano did not view the medical teaching and practice from which he made his living merely as a source of income to support his other intellectual pursuits. His medical works were punctuated with many of the interests and beliefs that received full expression in his other writings. Subtlety underpins his ideas about medical understanding and the power to cure. Cardano's belief in astral powers and the significance of the heavenly clock were intellectual principles that profoundly influenced his medicine. 

This is a life that provides an entry point into the interpenetration of sixteenth century medical culture and the wider intellectual universe of natural and moral philosophy, descriptive, mathematical and occult sciences. It also alerts us to the opportunities for and barriers to medical innovation including the clash of old and new traditions, the expected forms of intellectual debate, personal rivalries, institutional pressures and the demands of pedagogy. 

Source: Siraisi, N (1997) The Clock and the Mirror: Girolamo Cardano and Renaissance Medicine, Princeton University Press.