A malicious itinerant surgeon extracting stones from a grimacing patient's head; symbolising the extraction of 'folly' (insanity). Mezzotint by J. van der Bruggen after D. Teniers.

The images of a surgeon (often itinerant) making an incision in a patient's head in order to extract 'stones' (implying madness in the individual) do not represent an actual operation, but are allegorical scenes refering to the subduction of 'folly' (madness) from the body. See further: W. Schupbach, A new look at The cure of folly, Medical history, 1978, vol. 22, pp. 267-281