Reserve is proof of Prudence.

Reserve is proof of Prudence. The tongue is a wild beast; once let loose it is difficult to chain. It is the pulse of the soul by which wise men judge of its health: by this pulse a careful observer feels every movement of the heart. The worst is that he who should be most reserved is the least. The sage saves himself from worries and embarrassments, and shows his mastery over himself. He goes his way carefully, a Janus for impartiality, an Argus for watchfulness. Truly Momus had better placed the eyes in the hand than the window in the breast.