This paper compares within the MAS framework two separate threads in the formal study of epistemic change: belief revision and argumentation theories. Belief revision describes how an agent is supposed to change his own mind, while argumentation deals with persuasive strategies employed to change the mind of other agents. These are two sides (cognitive and social) of the same epistemic coin: argumentation theories are incomplete, if they cannot be grounded in belief revision models – and vice versa. Nonetheless, so far the formal treatment of belief revision mostly neglected any systematic comparison with argumentation theories. In MAS such problem becomes evident and inescapable: belief change is usually triggered by communication and persuasion from other agents, involving deception, trust, reputation, negotiation, conflict resolution (all typical issues faced by argumentation-based models). Therefore, a closer comparison between belief revision and argumentation is a necessary pre...