Unknowable truths and surprise parties: using the Knowability Paradox to address the self-effacing reasons problem

Normative reasons are considerations that count in favour of someone’s actions. According to a widely accepted epistemic constraint in the philosophy of normativity, relevant reasons for action are those that the agent knows or can come to know. This constraint is challenged by counterexamples, such as Schroeder’s (2007) surprise party scenario. Consider Nate, who loves a successful surprise party. The fact that a surprise party is being thrown for him constitutes a good reason for him to return home, where the party is taking place. However, if Nate were to know about the party, it would no longer be a surprise, thereby undermining the reason itself. The surprise party is an instance of a self-effacing reason, which is a fact that ceases to be a reason once the agent knows it. Carrara and Fassio (2024) highlight a connection between the challenge posed by self-effacing reasons to the epistemic constraint and the Church-Fitch Paradox. Building upon their findings, this research explores how the approaches of Hand and van Benthem to the knowability paradox can provide novel insights into the debate on self-effacing reasons. This study also provides a concise overview of the state of the art of both the Knowability Paradox and the self-effacing reasons problem. Emphasis is specifically placed on a recent reply to the Knowability Paradox by Goodsell et al. (forthcoming), on which some critical remarks have been developed in collaboration with Carrara and Fassio. The Knowability Paradox remains an ongoing subject of debate, raising new responses and contributions across different areas of philosophy.