Supposedly, this shows that the character is of high intelligence or at least education, because Smart People Know Latin. Perhaps a reason for this is that since nobody speaks Latin, its remaining uses include a large proportion of "scholarly" applications, such as etymology, deciphering ancient texts, and mere quotation. While other languages have uses in these fields, their primary use - as a living language - crowds out other uses, so they are not considered as "scholarly."
Based onTruth in Television, as back during the Renaissance when classical Greek and Roman texts were rediscovered by Europeans, the ability to read the original sources was considered a good idea. Even earlier, most literate Europeans were members of the clergy, and therefore had Latin as a common language regardless of where they were living. Given the above, Latin became the default language of scholarship, and works on science and other learned subjects were often written in Latin as a sort of Lingua Franca. This is one of the reason science's language of choice for terminologies (especially in taxonomy) is Latin (with some Greek thrown in). The trend only started to fade during the 19th century, when English was beginning to become dominant.
Further, knowledge of Latin (and to a lesser extent, Greek) was a sign of a proper education as supplied by the British Public School system. In other words, only the wealthy could afford an education that included instruction in Latin, thus the modern connotation of class and education. Also, education in Latin in the present day has been linked to better language skills and test scores, and it is rare for poor students to take Latin unless it's a requirement. Not to mention how many higher-end schools and universities havePretentious Latin Mottoes.
In modern works, knowledge of Latin will often be a part ofInstant Cultured if a character is subject toScrew Learning, I Have Phlebotinum. Expect a newly intelligent character to suddenly be able to read Latin fluently, or at least ramble off the Latin roots of a word.
Sebastian and Ciel inBlack Butler. Sebastian even goes undercover as a Latin teacher. Various other characters would also have studied Latin, given the time period, though the story doesn't confirm it for most of them.
In one issue ofThe Avengers, Hank McCoy (The Beast) converses with a Roman Catholic nun in Latin.
Asterix, which takes place around 50 BC when Latin was a living language, always show the Romans speaking the same language as the Gauls. Except that whenever a group of Roman legionnaires are speaking, then one of them will likely be qouting something in Latin. Often to the frustration of the other legionnaires since it usually happen in a situation too serious for that - for example while running from the invincible Gauls.
One of the pirates whose ship the Gauls wreckOnce Per Episode also has a tendency to offer pithy quotes in Latin when they're all floating on a raft.
In the filmEvent Horizon, the use of Latin by the captain of that ship on itsApocalyptic Log seems to be there partly to suggest what an educated guy he is, although it's themistranslation of one of the quotes by the protagonists that turns out to be relevant to the plot.
Scarlet fromIron Man 2 speaks multiple languages including Latin, which impresses Tony. Pepper, corrects him in saying no one 'speaks' Latin, as it's a dead language. This is correct, but not in the way the writers intended: The actual pronunciation for Latin is largely lost and thus nobody alive today would be comprehensible to a native speaker. Modern examples use Italian standards which creates oddities like "Caesar" being pronounced differently from the many languages where it is a loanword (such as German's "Kaisar", which scholars believe is the way it would have been pronounced in Latin).
In the live-actionRichie Rich movie, Cadbury is seen to be skilled in reading Latin. Richie himself apparently knows enough Latin to send him a secret message in a greeting card:
It's a running gag onQI to make fun ofStephen Fry's perceived posh upbringing. On one occasion, Alan made a joke about him knowing the Lord's Prayer in Latin, to which Stephen responded by quoting the first line of such at high speed.Here's the clip
An episode ofSliders had the protagonists end up in a world where being smart and well-educated is cool (they pass a punk on the street with a boombox blasting classical music). Sports are all a mix of physical endurance and knowledge (kinda lends a whole new meaning to the term "mathlete"). Quinn in this world is a well-known athlete and a slider (although,Quinn-prime finds out that this Quinn never discovered sliding and was just faking). He's also involved with some unsavory types. The episode'sBig Bad is a mobster who constantly likes to quote phrases in Latin and gets annoyed when the others have no idea what he said. At the end of the episode, right before sliding, Quinn turns around and spouts a phrase in Latin, which turns out to be an insult. Of course, it's entirely possible that many people know at least some Latin in this world, given the obsession with intelligence.
Gil Grissom has done this a time or two onCSI-his insect names are most common, but there has been once or twice besides that.
Fred and Wesley onAngel. Angel himself is a bit of an inversion, he does have his smart areas, but isn't really upper class. He probably learned some as a youth, and the rest from experience with the old books.
Methos onHighlander. Justified since he was alive back then and lived in the Roman Empire for a while.
Apparently Latin is part of the curriculum at Starfleet Academy for some reason, as one episode ofStar Trek: The Next Generation reveals that Wesley Crusher is studying it, and in another episode, Counselor Troi suggests that Picard, who's been turned into a child in a transporter accident, can go there to "brush up on [his] Latin."
Dorothy L. Sayers'Lord Peter Wimsey and Harriet Vane. They trade all sorts of learned quotations, but Latin is part of the deal. The last time he proposes marriage to her (inGaudy Night), he does so in Latin while wearing his cap and gown (he took a First at Balliol). She accepts in the same language: "Placet."[3] One of his frequent terms of endearment for her is "domina" (a feminine form of "dominus" "master") meaning "lady" or "mistress".
The theAubrey-Maturin series, this is invoked in universe. Stephen Maturin is a physician that speaks Latin (along with a half a dozen other languages) and he will often use Latin around patients both to keep them from knowing what he is saying (when he is talking to another physician or an assistant who also speaks Latin) and because patients are reassured by the fact that their doctor is learned enough to speak Latin. The crews of the ships he serves on often brag that their ship has a real physician that speaks Latin and Greek.
Note that these were the times when surgeons and physicians were two radically different occupations, surgeons being little more than half-literate artisans who could let the blood, put on the leeches, extract the tooth orperform a field amputation. Having a real trained doctor on the ship (which was required to have asurgeon, not a physician) was a rare luck indeed.
Vlad Tepes and Elizabeth Bathory are apparently writing to each other in Latin inCount and Countess.
Parodied in aFoxTrot strip where Jason says that his new year's resolution is to speak entirely in Latin. He recites common-knowledge Latin phrases such as "a priori", "quid pro quo", etc. just to annoy his sister, Paige.
InFallout: New Vegas your player can use Latin phrases in certain trees provided their intelligence is 8 out of 10. The lower ranks of Caesar's Legion seem only to know "vale" and "ave", while a centurion POW you meet seems to be fluent.
Phase (Ayla Goodkind) of theWhateley Universe reads Latin, ancient Greek, and Middle English, all part of his classism and upper-upper-class upbringing in private schools. He also speaks several modern languages, and is a snob about it.
Lisa: I'm the best student in school, how come I never heard about this competition? Bart: Maybe because you are, as we say in Latin, a "dorkus malorkus." Lisa: That's not Latin. Mom, Bart's faking it. Marge: Lisa, you've had your glory. Now it's Bart's turn.
There are countries where Latin and ancient Greek are still taught in school.
The non-english nomenclauture of anatomy, the "Terminologia Anatomica" is in latin (and is taught at medical universities in non-english speaking countries). It can be foundhere. Medicine itself is filled with Latin terminology, and generally, the language of medicine in non-english speaking countries is still latin.
In seminary (studying to be a priest), learning Koine Greek or Hebrew is usually compulsory, so that one can readThe Bible in its original language.
Mensa, the high IQ society, has a Latin name. "Mensa" means "table" in latin, signifying the coming together of equals.