The tongue should be prudently restrained, but not completely tied up. It is written: Whoever is wise will keep silence until the right moment. In other words, when it is seen that speech would be opportune the censorship of silence is relaxed, and an effort made to speak some appropriate word. Elsewhere it is written: There is a time to keep silence and a time to speak. Different circumstances should be prudently judged; the tongue should not be unprofitably loosened in speech when it ought to be restrained; nor should it indolently withhold speech when it could speak with profit. Reflecting well upon these things, the psalmist says: Set a guard over my mouth, O Lord, and a door of discretion before my lips. He does not ask for a wall to be set before his lips but a door, in other words, something that can be opened and closed. We must take care to learn, then, when we should discreetly and at the proper time open our mouths to speak, and when we should keep them closed and preserve a fitting silence.
St, Gregory the Great,
Regula Pastoralis, 3.14 (PL 77:72-4)
