Here the study of Bossuet's Discours sur l'histoire universelle exerted a profound influence upon him, and in 1756 he was received into the Catholic Church by the Archbishop of Paris.
Upon the outbreak of the war between France and England in the same year, he went to Spain, where he enlisted in a regiment of dragoons, and afterwards became a student at the military academy of Barcelona.
He soon abandoned, however, the idea of a military career, and went to Belgium, where he entered the Carthusian monastery at Nieuwpoort, at that time the sole English house of the order.
He became prior of his monastery in 1764, but left the order thirteen years later, after having obtained a Bull of secularization and also the privilege of possessing a benefice.
The invasion of the French in 1794 forced him to leave Belgium, and, after travelling in Germany and England, he finally settled at Prague, where he continued his literary labours until his death in 1809.