Vagueness and Responsibility

Date: October 8, 2025 (Wed)

Time: 15:30 – 17:00

Venue: Room 10.13, 10/F, Run Run Shaw Tower, Centennial Campus, HKU

Speakers:

Professor Maximilian Kiener

Philosophy & Ethics in Technology at Hamburg University of Technology

Abstract:

The philosophy of responsibility often assumes, or at least implies, that responsibility is a precise concept. That is, it makes the metaphysical or ontological claim that, despite our limited epistemic capacities, there is always a clear matter of fact as to whether someone is responsible or not, with no room for genuine indeterminacy. In this talk, I challenge this assumption by exploring the idea that responsibility is, instead, a vague concept. This alternative suggests the existence of a grey area where no metaphysical or ontological fact definitively determines whether someone is responsible. I first support the vagueness of responsibility by highlighting key features such as imprecise gradability, lack of clear boundaries, and tolerance. I then introduce an unconventional approach to addressing this vagueness: the normative power of taking responsibility after the fact. I propose that this normative power enables individuals to navigate moral vagueness by transitioning their status from indeterminate to determinate responsibility by mere declaration. This power is not about creating responsibility ex nihilo, but only about resolving vagueness where responsibility is indeterminate. Drawing on contractualist frameworks, I argue that no one could reasonably reject a principle granting this power, given its potential to address significant values in three domains: morality, by fostering moral reasoning and action; relationships, by reinforcing trust and accountability; and identity, by affirming one’s agential self-conception. To ensure this power is not misapplied, I propose two conditions: failure of a quality of will test (to preclude cases of already established responsibility) and the absence of a denial, i.e. a specific type of defence (to preclude cases without any link to the agent taking responsibility). 

Don’t miss Prof. Kiener’s another talk at the AI & Humanity Lab – Deep Ethics on October 10, 2025.