Numerous theories have been proposed for the causes of dancing mania, and it remains unclear whether it was a real illness or a social phenomenon. One of the most prominent theories is that victims suffered from ergot poisoning, which was known as St Anthony’s Fire in the Middle Ages. During floods and damp periods, ergots were able to grow and affect rye and other crops. Ergotism can cause hallucinations, but cannot account for the other strange behaviour most commonly identified with dancing mania...

Religio Medici (The Religion of a Doctor) sets out Sir Thomas Browne's spiritual testament as well as being an early psychological self-portrait. In its day, the book was a European best-seller. It was published in 1643 by the newly-qualified physician, and its unorthodox views placed it swiftly upon the Papal Index Librorum Prohibitorum in 1645. Although predominantly concerned with Christian faith, the Religio also meanders into digressions upon alchemy, hermetic philosophy, astrology, and physiognomy...