Rationality and reasoning. Debates from logic, philosophy, and cognitive science

The focus of my thesis is on the so-called rationality debate. In the first paper, I defend the desirability of the irrationalist explanation of group polarization against an argument put forward by Dorst (2024). The question of whether it is desirable to evaluate polarization (and related phenomena) as irrational is distinct from the question of whether such an evaluation is correct. I argue that the latter should be answered case by case, following the approach suggested by Crupi and Girotto (2014), which consists in construing both diagnoses of irrationality and attempts to rescue full rationality as logical arguments. In the second paper, I apply this method to the branch of the rationality debate centering on base-rate neglect. A logical reconstruction shows that disagreement is due to different interpretations of the experimental inputs or outputs. Since such interpretations can be tested empirically, I argue-contrary to Elqayam and Evans (2011)-that some rationality wars can be largely settled this way. Current evidence points to the reality of the base-rate fallacy. The third paper proposes a confirmation-theoretic explanation of base-rate neglect understood as a bias. This account, alongside two alternatives (based on representativeness and linear integration), is tested against data collected by Pighin and Tentori (2021), and proves more supported than the others. The fourth and fifth papers address another branch of the rationality debate revolving around conditional reasoning. The fourth shows that the suppositional account of conditionals has three normatively relevant properties: evaluation-mapping, logic-mapping, and faithfulness-to-intuition. The fifth assesses three inferentialist accounts-Rott’s (2023) difference-making and dependence accounts, and Crupi and Iacona’s (2024) evidential account-and argues that only the evidential one satisfies all three features to a considerable extent. I conclude by exploring a unitary inferentialist framework.