Communicating verbally in order to influence a person's attitudes or behaviour without duress.
Persuading people about some new attitude or action allows them the freedom to choose whether they wish to accept it or not. Such a decision is stronger and more reliable than one evoked by coercion.
Persuasion may be termed a form of "hidden violence", all the more lethal because it is a form of coercion which is harder for its victims to resist than outright physical coercion.