Plutarch, De garrulitate
Goodwin, Ed.

And yet there is no member of human bodies that Nature has so strongly enclosed within a double fortification, as the tongue, entrenched within with a barricado of sharp teeth, to the end that, if it refuses to obey and keep silent when reason ‘presses the glittering reins’ within, we should fix our teeth in it till the blood comes, rather than suffer the inordinate and unseasonable din. For, according to the saying of Euripides,

Our miseries do not spring
From houses wanting locks or bolts;
But from unbridled tongues,
Ill used by prating fools and dolts.

And truly, I must tell you, that they who think that houses without doors, and purses without strings, are of no use to their masters, yet at the same time set neither fence nor door before their lips, but suffer a continual torrent of vain and idle discourse to flow through them, like the perpetual flux of water through the mouth of the Pontic sea, seem to me to have the least esteem for human speech of all men in the world. Whence it comes to pass that they never gain belief, which is the end of all discourse. For the main scope and intention of all men that speak is to ¹ [p. 224] gain a belief of what they utter with those that hear them; whereas talkative noise-makers are never believed, let them speak never so much truth. For as wheat, when crowded into a musty vessel, is found to exceed in measure, but to be unwholesome for use; so the discourse of a loquacious person swells and enlarges itself with lies and falsehood, but in the mean time it loses all force of persuasion.