He was born in Paris into a wealthy family, the son of Nicolas de Pâris, Lord of Branscourt, Machault and
Pasquy (1658–1714), and a member of the Parlement of Paris. His mother, Charlotte Rolland, was the daughter of the mayor of Reims. According to biographies published after his death, he was tutored as a young boy by Augustinians at Nanterre. Originally destined for a career in law, he went against his father's wishes and chose a career in the Church instead. In 1712 a bout of smallpox left his face horribly scarred, "an affliction for which he thanked God". In 1713, at the age of 23, three months after the death of his mother in April, he entered the seminary of the Oratory of St. Magloire, where he studied the scriptures. In December 1713, his father Nicolas de Pâris made a will deposited with a notary before he died in March 1714. François opposed the bull Unigenitus, which condemned Pasquier Quesnel's annotated translation of the Bible. He then gave further support to the Jansenists. After three years at the Oratory, Pâris was ordained a deacon. During his time there he gave to the poor his annual family pension, and there is evidence to suggest that he turned down a position at canon of Reims Cathedral in 1718 or 1719 because of his humble stance. During his later career he was associated with the
College of Bayeux in Paris, a haven for Jansenist priests and follows, disturbed by the Church hierarchy or the authorities.
François de Pâris, Diacre Paris
François de Pâris retired to a modest house in
Faubourg Saint-Marceau, Paris, where he led a very austere life. Indeed, his living condition was so lowly that he "lodged in a hutch of planks set up in a courtyard, wore a hair shirt, and ate one meal a day, all while knitting stockings for the poor and giving advice to those who asked for it. He modeled himself after St. Francis and was apparently considered a local saint by many. His life has been described as one of "heroic humility".
During the final years of his life, Pâris became increasingly reclusive, and his ascetic lifestyle became increasingly severe, and he practised self-flagellation:
His bare feet became cut and bruised from walking on the paving stones ... He slept on an old armoire, covered himself with a sheet bristling with iron wires that tore his flesh ... He wore a hair shirt, a spiked metal belt, and a chain around his right arm. He beat himself with an iron-tipped lash until the blood ran down his back. He lit no fire for warmth even during the coldest winter days.