Fear and Loathing in Las Vegas is Thompson's most famous work, and is known as "Fear and Loathing" for short; however, he later used the phrase "Fear and Loathing" in the titles of other books, essays, and magazine articles.
Moreover, "Fear and Loathing", as a phrase, has been used by many writers, the first (possibly) being Friedrich Nietzsche in The Antichrist. In a Rolling Stone magazine interview, Thompson said: "It came out of my own sense of fear, and [is] a perfect description of that situation to me, however, I have been accused of stealing it from Nietzsche or Kafka or something. It seemed like a natural thing."
He first used the phrase in a letter to a friend written after the Kennedy assassination, describing how he felt about whoever had shot President John F. Kennedy. In "The Kentucky Derby is Decadent and Depraved", he used the phrase to describe how people regarded Ralph Steadman upon seeing his caricatures of them.
Jann Wenner claims that the title came from Thomas Wolfe's The Web and the Rock.