Reason as a Post-Hoc Construct: A Neurophilosophical Analysis of Rationality Without a Central Faculty
PhilPapers (PhilPapers Foundation) April 2, 2026 Ally Delshad Tehrani
Rationality is not a unified mental faculty but emerges from interactions among multiple brain subsystems, including predictive processing, distributed valuation, and prefrontal control. Coherent reasoning is reconstructed after the fact through narrative alignment, social expectations, and cultural standards, making rationality a post-hoc attribution rather than an intrinsic property of decision-making. This challenges the assumption that agency requires a centralized rational capacity, proposing instead a graded model of regulation where responsibility depends on varying neural and contextual constraints. The paper shifts from faculty-based to process-based accounts of cognition, with implications for philosophy of mind, cognitive science, and neuroethics.