A candor affected is a dagger concealed.

Marcus Aurelius (AD 121-180) Roman emperor (161-180), Stoic philosopher

Meditations, Book 11, #15 [tr. Staniforth (1964)]
    (Source)

Alternate translations:

• "But the affectation of simplicity is nowise laudable." [tr. Casaubon (1634), #14]
• "An affectation of being real, is an untoward pretence." [tr. Collier (1701)]
• "But the affectation of simplicity is like a crooked stick." [tr. Long (1862)]
• "An affectation of sincerity is a very dagger." [tr. Zimmern (1887)]
• "But the affectation of simplicity is like a razor." [tr. Farquharson (1944)]
• "But false straightforwardness is like a knife in the back." [tr. Hays (2003)]