'...often those who are overtly silent, when they suffer some injustice, develop a greater pain because they do not speak about what they endure. For if their tongues spoke calmly about what they suffered, the pain would fade from consciousness. For wounds that are enclosed are more painful. But where the pain that burns internally is released, the wound is opened for healing. They should know, therefore, that they aggravate the seriousness of their pain by withholding all speech when they become annoyed. They are to be advised, therefore, that if they love their neighbors as themselves, they should not keep silent about the things that justly deserve censure. For by the medicine of the voice, both parties can receive healing: for the one who inflicted the harm, his evil actions are checked, and the one who sustained the pain is relieved by releasing his wound.'
Gregory the Great, The Book of Pastoral Rule, p.122.