The most sacred duty is filial piety. “God showers his blessings on him who honors and reveres the author of his days,” says Pampelus (De Parentibus, Orelli, op. Cit., ii, 345). Ingratitude towards one’s parents is the blackest of all crimes, writes Perictione ( ibid.,p. 350), who is supposed to have been the mother of Plato.