The heresy of 'Jansenism', as stated by subsequent Roman Catholic doctrine, lies in the denial of the role of Free Will in the acceptance and use of grace. Jansenism asserts that God's role in the infusion of grace cannot be resisted and does not require human assent.
François de Pâris (1690–1727) was a Parisian Jansenist and a popular religious ascetic whose tomb in the parish cemetery at Saint-Médard gave rise to the convulsionnaire phenomenon.
In July of 1731, as the controversy over the growing cult at Saint-Médard grew, a woman named Aimée Pivert came to François de Pâris’s tomb seeking a cure for some neurological disorder. This illness may have been epilepsy, for upon touching the tomb, she was sent into spasmic contortions, causing some to think her possessed.
Almost every day for a month, she experienced these convulsions at Saint-Médard, until finally she went away claiming she’d been cured. Two weeks later, some other women appeared to convulse at the tomb and then claimed to have been healed, one of them asserting that she had regained the powers of speech and hearing after the experience.
Pilgrimages to the tomb of Paris continued and during this period, roughly a dozen pilgrims declared that they had been miraculously cured at the tomb.
This number of miracle cures exploded in 1731. Over 70 cures were announced that year, from a variety of ailments which included paralysis, cancer, and blindness, among others. Not surprisingly, the number of pilgrims also grew rapidly during the summer of 1731. Miracles were not necessarily unusual in this period, but the connection with Jansenism was considered a cause for suspicion.