He was now in his twentieth year; he quickly obtained the professorship of philosophy at the college in his native town, but soon resigned the position on account of ill-health.
Returning home in 1828, Crétineau-Joly accepted a chair of humanities at the Little Seminary of La Rochefoucauld, which he again had to quickly resign due to his health.
His first book, Melanges, was published in 1833 and dedicated to Marie-Caroline of Bourbon-Two Sicilies, Duchess of Berry, who had recently instigated a revolution in the Vendée.
The work brought him repute on account of the animated descriptions, the clear arrangement of the great mass of material, and his painstaking care in the use of authorities.
[4] In May of 1846, Pope Pius IX met personally with Crétineau-Joly in the Quirinal Palace, and asked him to write a history of secret societies.