Belief Revision (Belief Change, Belief Dynamics, Theory Change) is a research area in Formal Philosophy that makes use of Logic to produce models of how human and artificial agents change their beliefs in response to new information. The properties of these models are investigated in order to improve our understanding of how beliefs can be changed, with a particular emphasis on what it means to change one’s beliefs in a rational way.
In my PhD Thesis, supervised by Marcelo Coniglio in collaboration with Márcio Ribeiro, Belief Revision was used to provide a novel epistemic interpretation to Paraconsistency – by means of Paraconsistent Belief Revision systems. In the latter work (and most of my subsequent works), paraconsistency is studied from the perspective of epistemic attitudes of acceptance and rejection.
Roughly speaking, and from the perspective of belief dynamics, the acceptance of a belief-representing sentence (namely, a new piece of information) is not a sufficient condition for retracting its negation from a given epistemic state. As we understand it, such unnecessary retraction hurts the rationality principle of informational economy – a feature that I call as ‘the cost of consistency’.