Question: Which philosophy is associated with the French philosopher, known for his play, which later became a film directed by Vittorio De Sica?

Context paragraphs:
Jean-Paul Sartre: Jean-Paul Charles Aymard Sartre ( ; ] ; 21 June 1905 – 15 April 1980) was a French philosopher, playwright, novelist, political activist, biographer, and literary critic.  He was one of the key figures in the philosophy of existentialism and phenomenology, and one of the leading figures in 20th-century French philosophy and Marxism.

Anna of Brooklyn: Anna of Brooklyn (Italian: "Anna di Brooklyn" ) is a 1958 comedy film by Italian directors Vittorio De Sica and Carlo Lastricati.  It stars Gina Lollobrigida and Vittorio de Sica.

Count Max (1957 film): Count Max (Italian:Il conte Max) is a 1957 Italian-Spanish comedy film directed by Giorgio Bianchi and starring Alberto Sordi, Vittorio De Sica and Anne Vernon.  It is a remake of the 1937 film "Il signor Max" in which De Sica had played the title role.  This film was itself remade in 1991.

Two Women: Two Women (Italian: La ciociara ] , roughly translated as "The [Woman] from Ciociaria") is a 1960 Italian film directed by Vittorio De Sica.  It tells the story of a woman trying to protect her young daughter from the horrors of war.  The film stars Sophia Loren, Jean-Paul Belmondo, Eleonora Brown, Carlo Ninchi and Andrea Checchi.  The film was adapted by De Sica and Cesare Zavattini from the novel of the same name written by Alberto Moravia.  The story is fictional, but based on actual events during what the Italians call Marocchinate.

The Voyage (film): The Voyage (Italian: Il viaggio , and also released as "The Journey") is a 1974 Italian drama film directed by Vittorio De Sica and based on a novel by Luigi Pirandello.  It was De Sica's final film.

Heart and Soul (1948 film): Heart and Soul (Italian: Cuore , also known as "Heart") is a 1948 Italian drama film directed by Vittorio De Sica and Duilio Coletti, based on Edmondo de Amicis' novel Heart.  De Sica won the Silver Ribbon for Best Actor by the Italian National Syndicate of Film Journalists.

Red Roses (1940 film): Red Roses (Italian: Rose scarlatte ) is a 1940 Italian comedy film directed by Vittorio De Sica and Giuseppe Amato.  It was De Sica's first film as a director.  De Sica had previously appeared in a 1936 production of the stage play by Aldo De Benedetti on which it was based.

Count Max (1991 film): Count Max (Italian:Il conte Max) is a 1991 French-Italian comedy film directed by Christian De Sica and starring De Sica, Ornella Muti and Galeazzo Benti.  It is a remake of the 1957 film "Count Max", which was itself a remake of the 1937 film "Il signor Max".  Both films had starred Christian De Sica's father Vittorio De Sica.

The Condemned of Altona (film): The Condemned of Altona (Italian: I sequestrati di Altona ) is a 1962 Italian-French drama film directed by Vittorio De Sica.  It is based on the play of the same name by Jean-Paul Sartre.  For this film Vittorio De Sica won the David di Donatello for Best Director.

Un garibaldino al convento: Un garibaldino al convento is a 1942 Italian drama film directed by Vittorio De Sica.  It was screened in November 1991 as part of a retrospective of De Sica's films at the Museum of Modern Art.

Supporting paragraphs: The Condemned of Altona (film) Jean-Paul Sartre
Answer: the philosophy of existentialism