Quis custodiet ipsos custodes?
Quis custodiet ipsos custodes? is a Latin phrase found in the work of the Roman poet Juvenal from his Satires (Satire VI, lines 347–348). It is literally translated as "Who will guard the guards themselves?", though it is also known by variant translations, such as "Who watches the watchers?" and "Who will watch the watchmen?".
The original context deals with the problem of ensuring marital fidelity, though the phrase is now commonly used more generally to refer to the problem of controlling the actions of persons in positions of power, an issue discussed by Plato in the Republic. It is not clear whether the phrase was written by Juvenal, or whether the passage in which it appears was interpolated into his works.
The phrase, as it is normally quoted in Latin, comes from the Satires of Juvenal, the 1st–2nd century Roman satirist. Although in its modern usage the phrase has universal, timeless applications to concepts such as tyrannical governments, uncontrollably oppressive dictatorships, and police or judicial corruption and overreach, in context within Juvenal's poem it refers to the impossibility of enforcing moral behaviour on women when the enforcers (custodes) are corruptible (Satire 6, 346–348):
audio quid ueteres olim moneatis amici,
I hear always the admonishment of my friends:
Modern editors regard these three lines as an interpolation inserted into the text. In 1899 an undergraduate student at Oxford, E. O. Winstedt, discovered a manuscript (now known as O, for Oxoniensis) containing 34 lines which some believe to have been omitted from other texts of Juvenal's poem. The debate on this manuscript is ongoing, but even if the verses are not by Juvenal, it is likely that it preserves the original context of the phrase. If so, the original context is as follows (O 29–33):
... I know
Reference to political power
This phrase is used generally to consider the embodiment of the philosophical question as to how power can be held to account. It is sometimes incorrectly attributed as a direct quotation from Plato's Republic in both popular media and academic contexts. There is no exact parallel in the Republic, but it is used by modern authors to express Socrates' concerns about the guardians, the solution to which is to properly train their souls.
Several 19th-century examples of the association with Plato can be found, often dropping "ipsos". John Stuart Mill quotes it thus in Considerations on Representative Government (1861), though without reference to Plato. Plato's Republic though was hardly ever referenced by classical Latin authors like Juvenal, and it has been noted that it simply disappeared from literary awareness for a thousand years except for traces in the writings of Cicero and St. Augustine. In the Republic, a putatively perfect society is described by Socrates, the main character in this Socratic dialogue.
Socrates proposed a guardian class to protect that society, and the custodes (watchmen) from the Satires are often interpreted as being parallel to the Platonic guardians (phylakes in Greek). Socrates's answer to the problem is, in essence, that the guardians will be manipulated to guard themselves against themselves via a deception often called the "noble lie" in English. As Leonid Hurwicz pointed out in his 2007 lecture on accepting the Nobel Memorial Prize in Economic Sciences, one of Socrates's interlocutors in the Republic, Glaucon, even goes so far as to say "it would be absurd that a guardian should need a guard."
The issue of the accountability of political power, traced back to different passages of the Old and New Testaments, received great attention in medieval and early modern Christian thought, especially in connection with the exercise of authority in the Church and in church-state relations. In the Protestant tradition it also animated the debate about who was to be the final arbiter in the interpretation of the Scriptures.
In his 2013 report to the UN Human Rights Council, Alfred-Maurice de Zayas, the United Nations Independent Expert on the Promotion of a Democratic and Equitable International Order, elucidated Juvenal's continued relevance: “Crucial remains the conviction that the government should serve the people and that its powers must be circumscribed by a Constitution and the rule of law. Juvenal's question quis custodiet ipsos custodes (who guards the guardians?) remains a central concern of democracy, since the people must always watch over the constitutional behaviour of the leaders and impeach them if they act in contravention of their duties. Constitutional courts must fulfil this need and civil society should show solidarity with human rights defenders and whistleblowers who, far from being unpatriotic, perform a democratic service to their countries and the world.”
In popular culture
- The question "Who watches the watchmen?" often partially appears as graffiti scrawled in the background of Alan Moore and Dave Gibbons' graphic novel Watchmen, but the phrase is never seen in its entirety. Moore stated in an interview that the title of the series related directly to this question, although at the time of the interview Moore did not know where the sentence originated.
- It appears frequently in Terry Pratchett's Discworld novels, usually heard from Sir Samuel Vimes, commander of the City Watch. He answers it in Thud!, though very briefly, with the line "I do". When asked who watches over him, he follows it up with "I do, too". It also appears in Feet of Clay and I Shall Wear Midnight. It first appears in Guards! Guards! from a citizen, also addressed to Vimes, as: "Quis custodiet custard?"
- "Who Watches the Watchers" is an episode of Star Trek: The Next Generation involving a group of anthropologists who are observing a primitive culture from a concealed location, but are revealed following an accident.
- In Batman v Superman: Dawn of Justice, the phrase is handwritten on a floor support near the staircase as Batman carries a weakened Superman over his shoulder at the climax of their duel.
- Who Monitors the Birds, twelfth episode Space: Above and Beyond, makes reference to the saying.
- E. O. Winstedt 1899, "A Bodleian MS of Juvenal", Classical Review 13: 201–205.
- Recently J. D. Sosin 2000, "Ausonius' Juvenal and the Winstedt fragment", Classical Philology 95.2: 199–206 has argued for an early date for the poem.
- E.g. Who Are The Watchmen?; T. Besley and J.A. Robinson, "Quis Custodiet Ipsos Custodes? Civilian Control over the Military", Journal of the European Economic Association v. 8, pp. 655–663, 2010; and P. Corning, The Fair Society: The Science of Human Nature and the Pursuit of Social Justice,, University of Chicago Press, p. 146, 2011.
- Oxenham, H.N. (1878). "Moral and Religious Estimate of Vivisection". Gentleman's Magazine, and Historical Chronicle. 243 (Jul. to Dec): 732.
- Maguire, Thomas (1866). An Essay on the Platonic Idea. London: Longmans, Green, Reader, and Dyer. p. 39.
- Jayapalan, N. (2002). Comprehensive Study of Plato. Atlantic Publishers & Dist. p. 10.
- Plato (2008) [c. 380 BC]. The Republic. Benjamin Jowett, transl; EBook produced by Sue Asscher and David Widger. Project Gutenberg.
How then may we devise one of those needful falsehoods of which we lately spoke – just one royal lie which may deceive the rulers, if that be possible, and at any rate the rest of the city?
- Book III, XII, 403E, p. 264 (Greek) and p. 265 (English), in volume I, of Plato, The Republic (ΠΟΛΙΤΕΙΑ), with an English translation by Paul Shorey, London, William Heinemann Ltd.; New York: G. P. Putnam's sons, 1930, as cited by Leonid Hurwicz, " But Who Will Guard the Guardians?", Nobel Prize Lecture, December 8, 2007, Accessed April 27, 2011.
- Matis, Hannah W. (2019). The Song of Songs in the Early Middle Ages. Brill. pp. 117–38.
- Eco, Umberto (1984). Semiotics and the Philosophy of Language. Indiana University Press. p. 150.
- Guarino, Thomas G. (2013). Vincent of Lérins and the Development of Christian Doctrine. Baker Academic. p. 119.
- https://ap.ohchr.org/documents/dpage_e.aspx?si=A/HRC/24/38, paragraph 52
- Atkinson, Doug. The Annotated Watchmen. http://www.capnwacky.com/rj/watchmen/chapter1.html.[permanent dead link]
- Plowright, Frank. "Preview: Watchmen". Amazing Heroes. June 15, 1986.