Camus and Sartre admired each other's work before becoming friends

Camus and Sartre had a public falling out over communism

The two were close friends, sometimes collaborating throughout the 1940s, but the release of Camus' 1951 book, "The Rebel," led to a schism over differing views on communism.

Sartre admired American novelist William Faulkner

In addition to writing philosophy and fiction, Jean-Paul Sartre was also a literary critic. His 1939 essay on Faulkner's "The Sound and the Fury" focused on the way the American novelist commented on time, favorably comparing him to Marcel Proust. Ultimately, Sartre argues Faulkner's "despair" about a "closed future" is a result of the "social conditions of our present life." Ever the existentialist, though, Sartre suggests this reality is something that should inspire rather than depress.

The FBI kept tabs on Camus and Sartre

Jean-Paul Sartre worked as an American correspondent for Combat, the newspaper edited by Albert Camus. While he was in the States, J. Edgar Hoover's FBI kept tabs on him, concerned that Combat was publishing unfavorable portrayals of the US.

Sartre panned 'Citizen Kane'

Jean-Paul Sartre was primarily known for his philosophy, fiction, and drama, but he was also a critic. In 1945, he wrote a rather negative review of Orson Welles' "Citizen Kane," deriding Welles' decision to tell the story in the past tense, writing, "film in the past tense is the antithesis of cinema. Therefore 'Citizen Kane' is not cinema."

Sartre and de Beauvoir had an open romantic relationship

The two figureheads of existentialist thought were romantic partners, though they had a publicly open relationship and never lived together. As de Beauvoir says in the interview below, "third persons knew our relationship dwarfed any we could have with them."

Many writers considered 'existentialist' didn't identify with the term

“Existentialism” was first introduced in 1943 by philosopher Gabriel Marcel. Jean-Paul Sartre and Simone de Beauvoir readily adopted the term, but others, such as Albert Camus and Martin Heidegger, rejected it. Earlier philosophers, like Søren Kierkegaard and Friedrich Nietzsche, were long dead by the time the word was in vogue.

Camus was influenced by American culture, especially literature and jazz

He loved the work of writers like William Faulker and Ernest Hemingway, and loved drinking whiskey and listening to jazz. He also admired the actor Humphrey Bogart and his striking performance in the noir classic "The Big Sleep." He was delighted when his wife gave him a Burberry raincoat, thinking it made him look more like Bogart.

Read Albert Camus' 'Myth of Sisyphus and Other Essays'

Camus' most famous work of nonfiction is this collection of philosophical essays. Perhaps the most resonant entry is the title essay, which reimagines the Greek myth of a man condemned to roll a boulder for all eternity. Rather than presenting the story as a cautionary tale about defying the gods, as the original myth intended, Camus considered Sisyphus an "absurd hero" for his actions and imagined him smiling as he endlessly toiled at his repetitive punishment.

Camus credited a teacher with his success

After winning the Nobel Prize in literature in 1957, Camus wrote a letter to Louis Germain, his former teacher, thanking the man for "the affectionate hand" he extended to Camus as a student. In the short note, he'd go on to write, "without your teaching and example, none of all this would have happened."

Camus edited an underground newspaper during World War II

The paper, called "Combat," was aligned with the French Resistance fighting against the Nazi occupation. Like his fiction, his journalism was clear-eyed: When Hiroshima and Nagaski were bombed, he criticized the many writers impressed with the destruction, writing, "our technical civilization has just reached its greatest level of savagery."

Camus directed a Picasso-penned play

The show, called "Desire Caught by the Tail," was written by Picasso in 1941 while living in Nazi-occupied Paris. It was first staged in 1944, featuring several French intellectuals, including Albert Camus, who directed, as well as Jean-Paul Sartre and Simone de Beauvoir, who had starring roles.

An existentialist reading list

If you’re looking for a starting point for diving into existentialist thought, this is a great resource. Its titles are not exactly obscure—Albert Camus’ “The Stranger,” Franz Kafka’s “The Trial,” and Søren Kierkegaard’s “Either/Or” are among the most famous works in Western literature—but the list provides some digestible context for each text, which will help you decide the best place to begin your journey.

A Camus scholar believes 'The Stranger' is often misread as a role model

The writer and philosopher Jonathan Rée notes that part of the reason why the book was so popular was that it was an easy pick for students learning French to translate. What's often lost in translation, though, is that the book's narrator, Meursault, who murders a man, is not intended to be a role model.

Jean-Paul Sartre worked on 'Being and Nothingness' while a prisoner of war

The Nazis invaded France in May 1940. Sartre, as a member of the French Army, was taken prisoner that June. While he was in captivity, he studied Martin Heidegger and worked on "Being and Nothingness," one of his most famous philosophical works.

Camus contracted tuberculosis as a teenager

There was still little understanding of treatment for the disease at the time; for most people, a tuberculosis diagnosis was a death sentence. The 17-year-old Camus was quarantined in his uncle's house, where he grew into an avid reader. Scholars note that the experience would inform his later work, including his 1947 novel "The Plague."

A mescaline-induced hallucination stayed with Jean-Paul Sartre throughout his life

In 1935, Sartre was injected with mescaline, a psychedelic drug that was then used to treat alcoholism and depression, by his friend at the Hôpital Sainte-Anne in Paris. It was not a good trip: Sartre saw nightmarish crabs for days and suffered a mental breakdown. For the rest of his life, crustaceans like the ones he saw during the hallucination appeared in his works.

Sartre and de Beauvoir's literary journal was named after a Charlie Chaplin movie

The couple founded the magazine Les Temps Modernes in 1945 and it quickly became essential reading for French intellectuals. Its name came from "Modern Times," Charlie Chaplin's 1936 movie that satirized the industrial revolution's dehumanizing effects.

Sartre's 1980 funeral attracted a massive crowd

The legendary existentialist died April 15, 1980. A week later, mourners packed the streets of Paris to pay tribute. Estimates suggest that between 20,000 and 50,000 people were in attendance. In the Associated Press footage below, you can watch them following the hearse from the hospital where the thinker died to his resting place in Montparnasse Cemetery.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'

Basquiat and Warhol were friends and collaborators before a bitter falling out

The two men were tight, but they also offered what the other lacked in the art world: Basquiat inspired Warhol, and Warhol gave Basquiat art-world credibility. They began working together, producing 160 collaborative works between 1983 and 1985. A 1985 exhibition of their joint works was a massive flop, though, and the friendship never recovered.

Kurt Vonnegut's satire embraced dark humor

Books like "Cat’s Cradle" and "Slaughterhouse Five" satirized the international appetite for war, which the 20th-century writer found both horrifying and hilarious. It’s a combination that some called “gallows humor,” a classification Vonnegut himself remembered Sigmund Freud describing. “One of the examples Freud gives is a man about to be hanged,” Vonnegut once recalled, “and the hangman says, ‘Do you have anything to say?’ The condemned man replies, ‘Not at this time.’”

Salvador Dalí idolized Freud but was disappointed after they met

Sigmund Freud's writings on dreams and the unconscious profoundly influenced Dalí and his work, and the artist came to idolize the Austrian psychoanalyst. When they met, Freud viewed Dalí as an odd curiosity, and the artist came away disappointed, significantly lowering his opinion of the psychoanalyst.

Aldous Huxley wrote to George Orwell about '1984'

After reading "1984," Aldous Huxley wrote to his former student George Orwell, offering some praise for the recently released novel. The letter, though, offers much criticism, too, arguing that Huxley's vision in "Brave New World" of a world state that pacifies its citizens through overwhelming pleasure is the more likely—and more horrifying—nightmare.

In 1922, Zelda Fitzgerald was commissioned to write a satirical review of her husband's latest novel

The review of "The Beautiful and the Damned" might have been comedic, but it was also illuminating, allowing Zelda to acknowledge her husband's tendency to use material from her diaries in his fiction and interrogate the way female characters were often portrayed in novels written by men.

Famed poet TS Eliot rejected the manuscript for George Orwell's political fable 'Animal Farm,' writing that its criticism of authoritarianism was not 'the right point of view.'

Ralph Waldo Emerson celebrated Walt Whitman, then regretted it

Emerson famously praised the first edition of Whitman’s “Leaves of Grass,” which Whitman used to promote the collection. In doing so, Whitman effectively created the modern book blurb, though he did so without Emerson’s permission, leading to a prolonged, passive beef between the two.

Read the Beats' poetry

The Beats were alike in their willingness to experiment and transgress, though the movement’s writers were distinct artists with varying styles. This collection showcases the breadth of the Beat Generation’s work, with authorized texts from Allen Ginsberg, Jack Kerouac, Lawrence Ferlinghetti, Diane di Prima, Richard Brautigan and others.

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

Explore a list of the 100 best novels of all time, compiled by some of the world's best living writers, including Salman Rushdie, Stephen King, and Jennifer Egan.

Georgia O'Keeffe's flower paintings are often assumed to be sexual, though the artist claimed she was simply interested in highlighting the beauty of flowers that most people neglect

Mark Twain spent decades feuding with the US Postal Service, convinced its costs and regulations were bureaucratic overreach.

Mid-century modern graphic designers, known for their bright colors and bold lines in advertising, also found success with children's books.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography