Her theoretical articulation of parity inspired the French law which requires every political party to fill 50 percent of all candidacies in every seat with women.

[2][3] Agacinski is the mother of a son by philosopher Jacques Derrida, who directed the EHESS, and she became the stepmother of Lionel Jospin's two children with their marriage.

[5] As a feminist philosopher, Agacinski is associated with "differentialism", an important strain of French feminism, which argues that the human condition cannot be understood in any universal way without reference to both sexes.

[7][8] In 1999, Agacinski was a leading originator of a bill to amend article three of the Constitution of France to include a phrase stating: "The law will encourage equal access for women and men to political life and elected posts.

"[9] With Jospin's support, the so-called "Parité" ("Parity") amendment was made on June 28, 1999, and was followed by a law, on May 3, 2000, obliging the country’s political parties to present 50% female candidacies in virtually any race, or lose a corresponding share of their governmental campaign funding.