Conti was considered intelligent but due to a slight deformity and having a weak constitution[1] he was destined for a clerical career and studied theology at the university of Bourges, but although he received several benefices, including the abbeys of Cluny and Saint Denis,[2] he did not take orders.

He played a conspicuous part in the intrigues and fighting of the Fronde, became in 1648 commander-in-chief of the rebel army, and in 1650 was with his brother (Condé) and brother-in-law (Longueville) imprisoned at Vincennes.

[citation needed] (this might have been a symptom of the syphilis which would lead to his death) Having a secret passion for his sister the Duchess of Longueville, he invented tricks to make her notice him.

This episode was ultimately fortunate for him because he could no longer be refused external help from physicians, some of whom would pass letters and pleas to the outside world which sped up his eventual release.

[7] At Clermont, Conti had been a fellow student of Molière's, from whom he secured an introduction to the court of King Louis XIV, but afterwards, when writing a treatise against the stage entitled, Traité de la comédie et des spectacles selon les traditions de l'Église (Paris, 1667), he charged the dramatist with keeping a school of atheism.