
— Sókratés klasický řecký filozof -470 - -399 př. n. l.
Zdroj: O’TOOLE, Garson. Misbehaving Children in Ancient Times. Quote Investigator®<nowiki> [online https://quoteinvestigator.com/2010/05/01/misbehaving-children-in-ancient-times/. 2010 [cit. 2018-08-15]. Dostupné z: https://quoteinvestigator.com/2010/05/01/misbehaving-children-in-ancient-times/</nowiki>]
Zdroj: FREEMAN, Kenneth J a M. J RENDALL. Schools of Hellas: an essay on the practice and theory of ancient Greek education from 600 to 300 B.C. London: Macmillan and Co., limited, 1907.