The heart seldom feels what the mouth expresses.
Le cœur sent rarement ce que la bouche exprime.
Original text (French)
Source, in full
Pompéia (Paris: J. Chardon, 1688), Clodius, act II, sc. v, l. 458. First performed on 7 November 1687 at the Théâtre du Palais-Royal. Translated by Craufurd Tait Ramage, Beautiful Thoughts from French and Italian Authors (Liverpool: E. Howell, 1866), p. 63