這句話通常是以拉丁語來引述,原文來自1至2世紀羅馬諷刺作家尤維納利斯的諷刺詩集(英語:Satires of Juvenal)。然而,這句話具有普遍的現代用法,時常運用於例如暴虐專政、失控的壓迫性獨裁以及警察或司法的腐敗和逾矩等的場合。在尤維納利斯原詩內容中,是指當執法人員(custodes)腐敗時,對婦女實施道德行為是不可能的(亦即可能也會對婦女實施不道德的行為)(《Satire》6(英語:Satire VI).346–348):
拉丁語:
audio quid ueteres olim moneatis amici,
"pone seram, cohibe." sed quiscustodietipsos custodes? cauta est et ab illis incipit uxor.
英語:
I hear always the admonishment of my friends:
"Bolt her in, constrain her!" But who will guard the guardians? The wife plans ahead and begins with them.
拉丁語:
… noui
consilia et ueteres quaecumque monetis amici,
"pone seram, cohibes." sed quis custodiet ipsos— custodes? qui nunc lasciuae furta puellae
hac mercede silent crimen commune tacetur.
英語:
… I know
the plan that my friends always advise me to adopt:
"Bolt her in, constrain her!" But who can watch the watchmen? They keep quiet about the girl's
secrets and get her as their payment; everyone
hushes it up.
E.g. Who Are The Watchmen? (頁面存檔備份,存於互聯網檔案館); 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 an earlier version of the present article.
柏拉圖. 理想国. 本傑明·喬伊特(英語:Benjamin Jowett), transl; EBook produced by Sue Asscher and David Widger. 古騰堡計劃. 2008年 [c. 380 BC] [2013-03-18]. (原始內容存檔於2019-12-20). 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), 柏拉圖, 理想國(ΠΟΛΙΤΕΙΑ)卷一, 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? (頁面存檔備份,存於互聯網檔案館)," Nobel Prize Lecture, December 8, 2007, Accessed 4-27-2011.