这句话通常是以拉丁语来引述，原文来自1至2世纪罗马讽刺作家尤维纳利斯的讽刺诗集（英语：Satires of Juvenal）。然而，这句话具有普遍的现代用法，时常运用于例如暴虐专政、失控的压迫性獨裁以及警察或司法的腐败和逾矩等的场合。在尤维纳利斯原诗内容中，是指当执法人员（custodes）腐败时，对妇女实施道德行为是不可能的（亦即可能也会对妇女实施不道德的行为）（《Satire》6（英语：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? （页面存档备份，存于互联网档案馆）; 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.
柏拉图. 理想国. 本杰明·乔伊特（英语：Benjamin Jowett）, transl; EBook produced by Sue Asscher and David Widger. 古腾堡计划. 2008年 [c. 380 BC] [2013-03-18]. （原始内容存档于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), 柏拉图, 理想国（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? （页面存档备份，存于互联网档案馆）," Nobel Prize Lecture, December 8, 2007, Accessed 4-27-2011.
