(written from a Production point of view)
This page documents cases where a character in Star Trek has used an existing quote, but did not allude to the quote's origin. It does not include quotations which were identified within the story, as these are documented via their originator.
Star Trek: The Original Series
- In conversation with Gary Mitchell, Kirk talks about "Absolute power corrupting absolutely". That makes it one of several episodes in which a well known observation about power by Lord Acton is paraphrased. The original quote goes "Power tends to corrupt, and absolute power corrupts absolutely".
- Trelane addresses Yeoman Ross with a close paraphrase of a line from Doctor Faustus by Christopher Marlowe: "Is this the face that launched a thousand ships, and burnt the topless towers of Ilium? Fair Helen, make me immortal with a kiss." The actual line is "Was this the face that launch'd a thousand ships, And burnt the topless towers of Ilium?/ Sweet Helen, make me immortal with a kiss."
- McCoy says "Absolute power corrupts absolutely", which he describes as an Earth saying. That makes it one of several episodes in which a well known observation about power by Lord Acton is paraphrased. The original quote goes "Power tends to corrupt, and absolute power corrupts absolutely".
- While influenced by Kollos, Spock's voice quotes Lord Byron's "She Walks In Beauty" – "She walks in beauty, like the night." – to Nyota Uhura. He then paraphrases a line from William Shakespeare's The Tempest – "O brave new world, that has such creatures in it. " – substituting the word "creatures" for "people".
- A section of the poem "Last Poems XIX", by A. E. Housman, is recited by Marta, who claims it to be hers. The exact fragment is "In the midnight of November, when the dead man's fair is nigh. And the danger in the valley, and the anger in the sky". Martha had previously been called out for passing off a sonnet by Shakespeare as her own, but she was not chastised in this case.
Star Trek: The Next Generation
- Picard recalls the old saying "Power corrupts", which Riker completes with "And absolute power corrupts absolutely". That makes it one of several episodes in which a well known observation about power by Lord Acton is paraphrased. The original quote goes "Power tends to corrupt, and absolute power corrupts absolutely".
- In the final scene, Picard informs the bridge that "any rumours of my brush with death are greatly exaggerated", paraphrasing a quote attributed by Mark Twain; "The reports of my death are greatly exaggerated". Picard will later paraphrase the same quote in Star Trek: First Contact.
Star Trek: Deep Space Nine
- During a heated exchange with his brother about unionization of Quark's, Nog shrieks "Workers of the world, unite! You have nothing to lose but your chains!". This is a rallying cry closely adapted from The Communist Manifesto by Karl Marx and Friedrich Engels (see communism). The second sentence is often used but is somewhat mangled compared to the phrasing used in the manifesto.
- Garak in trying to sell a dress to Chalan Aroya says "A thing of beauty is a joy forever". This is an oft-quoted line from "Endymion", a poem by John Keats.
- Quark laments ""War! What is it good for? If you ask me, absolutely nothing.", paraphrasing a line from the anti-war song "War"
- An exchange between Nog and Jake Sisko has the latter saying, "Lions, Gigers, bears", to which Jake answers "Oh my". This is a paraphrase of a well-known quote from the 1939 film version of The Wizard of Oz, in which the character of Dorothy Gale says "Lions, and tigers, and bears! Oh, my". Writer Ronald D. Moore changed the character's name to Giger especially to accomodate this joke. (Star Trek: Deep Space Nine Companion, p.466)
Star Trek: Voyager
- The Doctor describes the Vulcan brain as "a puzzle wrapped inside an enigma housed inside a cranium". This is reminiscent of a quote by Winston Churchill, in which he described the the future actions of Russia as "a riddle wrapped in a mystery inside an enigma".
- The Doctor notes "The reports of my decompilation have been greatly exaggerated", paraphrasing a quote attributed by Mark Twain, though misquoted; "The reports of my death are greatly exaggerated".
Star Trek: Enterprise
- While eating Burgerland burgers and trying to be friendly to T'Pol only to be received coldly, Loomis says "Have it your way". While this is not an uncommon phrase, it is also a well-known Burger King slogan, allowing for the possibility that Loomis (or the writers) might have intentionally used the phrase as a witty reply, but this was not made explicit.
Star Trek: Discovery
- While exploring a Klingon ship which she finds to be beautiful, Michael Burnham notes that she can't remember who said "Sculptures are crystallized spirituality,". It appears to actually be a paraphrase of a quote by Amos Bronson Alcott, which reads, "Madame de Staël pronounced architecture to be frozen music; so is statuary crystallized spirituality." 
- While eulogizing Airiam, Sylvia Tilly paraphrases a quote from Albert Einstein. She notes, "Some people choose to live their lives as if nothing is a miracle. But Airiam fought for her life, and so everything was.", while the actual quote is, "There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."
Star Trek films
- Khan Noonien Singh quotes Moby Dick several times, apparently identifying with the obsessive captain Ahab in his campaign of revenge against Kirk. These include "To the last, I grapple with thee", later followed by the section immediately succeeding it in the book, "From Hell's heart, I stab at thee. For hate's sake, I spit my last breath… at thee.". In another instance, the former prince updates a sentence: "I'll chase him round the moons of Nibia and round the Antares maelstrom and round perdition's flames before I give him up". The original text says "I'll chase him round Good Hope, and round the Horn, and round the Norway Maelstrom, and round perdition's flames before I give him up"
- Captain Spock states "An ancestor of mine maintained that if you eliminate the impossible, whatever remains – however improbable – must be the truth." This is a well known quote by Sherlock Holmes not only in reality, but also identified as such in "Data's Day". Note that the ancestor must not be Sherlock Holmes, but could be his creator, Sir Arthur Conan Doyle.
- During the Klingon trial scene, general Chang after asking Kirk a question says "Don't wait for the translation – answer me now!". This keeps with the film's cold war theme as it paraphrases a demand made by American ambassador Adlai Stevenson of Soviet ambassador Valerian Zorin at the United Nations during the Cuban missile crisis in 1962. Stevenson's phrasing was "Don't wait for the translation — yes or no?". (Star Trek Encyclopedia (4th ed., vol. 1, p. 132))
- In the penultimate scene of Star Trek VI: The Undiscovered Country, when Pavel Chekov asks James T. Kirk where the next course will be, Kirk responds, "Second star to the right… and straight on 'til morning". This is from the Walt Disney animated film adaptation of Peter Pan. See the article on Peter Pan for more info.
- At one point in the movie, Tolian Soran says "time is the fire in which we burn". The quote comes from the poem "Calmly We Walk Through This April's Day" (also known as "For Rhoda") by Delmore Schwartz. The full poem can be read here. According to Ron D. Moore, the writing staff found the quote in Bartlett's Familiar Quotations. (AOL chat, 1997)
- Picard at one point says "Reports of my assimilation are greatly exaggerated", paraphrasing a quote attributed by Mark Twain; "The reports of my death are greatly exaggerated". Picard had previously reused the quote in "Samaritan Snare".
- Like his counterpart does in Star Trek VI: The Undiscovered Country, Spock notes that "If you eliminate the impossible, whatever remains – however improbable – must be the truth.", which is a Sherlock Holmes quote. While in Star Trek VI: The Undiscovered Country he attributed the quote to an ancestor, in this film he does not attribute it at all.
Several Star Trek episodes and movies have also drawn their titles from quotations. These include:
- TNG: "We'll Always Have Paris": A well-known line from the film Casablanca. The episode also mentions the Blue Parrot Café, which is another reference to the film.
- DS9: "Doctor Bashir, I Presume": a reference to the famous quote spoken by Henry Morton Stanley; "Doctor Livingstone, I presume?" Stanley was a reporter sent by the New York Herald to find Dr. David Livingstone in Africa. Livingstone was a missionary and explorer who had lost contact with the outside world for six years. When Stanley found Livingstone, he greeted him with those now famous words.
- DS9: "Wrongs Darker Than Death or Night": from the 1820 Percy Bysshe Shelley lyrical drama Prometheus Unbound. The full quotation reads "To suffer woes which Hope thinks infinite;/To forgive wrongs darker than death or night;/To defy power which seems omnipotent;/To love, and bear; to hope till Hope creates/From its own wreck the thing it contemplates;/Neither to change, nor falter, nor repent;/This, like thy glory, Titan, is to be/Good, great and joyous, beautiful and free;/This is alone Life, Joy, Empire, and Victory." It comes from Act IV, lines 572-580, serving as the epilogue of the play as spoken by Demogorgon.
- DS9: "In the Pale Moonlight": A reference to the phrase "Have you ever danced with the devil in the pale moonlight?" from the film Batman. (AOL chat, 1998)
- DIS: "Magic to Make the Sanest Man Go Mad": from Homer's Iliad, Book XIV, line 217 ("πάρφασις, ἥ τ᾽ ἔκλεψε νόον πύκα περ φρονεόντων"), in Robert Fagles' translation. It refers to Aphrodite's sash or girdle, a love charm which the goddess gives to Hera in order to beguile Zeus.
- DIS: "Saints of Imperfection": from a quote from Guillermo del Toro: "Monsters are the patron saints of imperfection."