Thérèse Philosophe is a 1748 French novel ascribed to Jean-Baptiste de Boyer, Marquis d'Argens. It has been chiefly regarded as a pornographic novel, which accounts for its massive sales in 18th-century France (as pornographic works were the most popular bestsellers of the time). Aside from that however, this novel represents a public conveyance (and arguably perversion) for some ideas of the Philosophes.
The narrative starts with Therese, from solid bourgeois stock, becoming a student of Father Dirrag, a Jesuit who secretly teaches materialism. Therese spies on Dirrag counseling her fellow student, Mlle. Eradice, and preying on her spiritual ambition in order to seduce her. Through flagellation and penetration, Dirrag gives Mlle. Eradice what she thinks is spiritual ecstasy but is actually sexual. "Father Dirrag" and "Mlle. Eradice" are named after anagrams of Catherine Cadière and Jean-Baptiste Girard, who were involved in a highly publicized trial for the illicit relationship between priest and student in 1730.
Therese is placed in a convent, where she becomes sick because her pleasure principle is not permitted to express itself, putting her body into disorder. She is rescued by Mme. C and Abbe T. and she spies on them discussing libertine political and religious philosophy in between sexual encounters.
Therese's sexual education continues with her relationship with Mme. Bois-Laurier, an experienced prostitute. This is a variation on the whore dialogues that were common in early pornographic novels.
Finally, Therese meets the unnamed Count who wants her for his mistress. She refuses him intercourse, out of her fear of death in childbirth (not unreasonable at the time). He makes a bet with her. If she can last two weeks in a room full of erotic books and paintings without masturbating, he will not demand intercourse with her. Therese loses and becomes the Count's permanent mistress.
For all of its printed debauchery, the work has some philosophical merit in its underlying concepts. Between the more graphically adult sections of the novel, philosophical issues would be discussed amongst the characters, including materialism, hedonism and atheism. All phenomena are matter in motion, and religion is a fraud, though useful for keeping the working classes in line.