ROGÉRIO FERNANDES MARTINS

This master's thesis examines, from a philosophical perspective, aspects of the intense polarization of beliefs and opinions presently observed in diverse social groups. More precisely, the analysis focuses on the persistence of fallacious explanatory discourses within these groups, expanding into a comprehensive study of their origin and perpetuation. Initially, the term "polarization" is defined as the shift in opinion towards extremes in groups composed of like-minded individuals following the occurrence of a deliberative event. Particular attention is paid to the most cohesive and persistently polarized groups, termed "epistemic bubbles". These are environments where individuals fail to distinguish between the thought that they know “p” and their knowing “p”. The fallacious explanatory discourse presented in these contexts is referred to as "compromised reason". This term encompasses two distinct interpretations. The first interpretation considers the expression "compromised reason" as dubious or flawed reasoning, raising the question: why are illegitimate explanations so persuasive within these bubbles? To examine this situation, an analysis that combines several theories is employed, including van Fraassen's pragmatic theory of explanation, Austin's speech act theory, and Grice's theory of implicatures. This analysis reveals that the strength and effects produced by an explanation do not necessarily depend on the truthfulness of its components. The second interpretation considers the expression "compromised reason" as the result of a group commitment, explaining the support and tenacity in defending fallacious discourses, even when they are heavily contested within these groups. In this approach, the study refers to the epistemology of groups and Gilbert and Priest's thesis on the negotiation of collective belief, asserting that group beliefs emerge from a collective linguistic negotiation, culminating in a mutual commitment to the utterances made within this context. This suggests the prevalence of group loyalty over epistemic reasons in the articulation of explanatory discourses within these groups, for instance. The considerations developed throughout the text facilitate the analysis and evaluation of interventions currently proposed to mitigate the effects of polarization while also suggesting a path for future research.