Agentive Modality in the Dialogical Roots of Deduction

Saam Nasseri

University of California, Riverside

The aim of Catarina Dutilh Novaes’ project in the philosophy of logic is to resituate deductive reasoning according to its genealogy. In her book The Dialogical Roots of Deduction, Novaes aims also to provide the historical evidence necessary to motivate an understanding of deduction as fundamentally social and discursive, i.e. in line with its genealogy, which culminates in a practice-based conception of logic and deduction that is multi-agential and dialogical – the Prover-Skeptic Model (PSM). The PSM is a rationally reconstructed schema which articulates the functional roles of the two cooperatively-adversarial perspectives, the Prover and Skeptic, necessary to instantiate deductive reasoning. In this paper I would like to situate the PSM within the context of abilities and ability ascriptions – specifically, the vocabulary of agentive modality. In the PSM, each inferential step is characterized by what an agent can or is able to do, or what they cannot but do if they cannot do something else. Agentive modals divide into ability modals and their duals, compulsion modals. Ability modals express what an agent can, or is able to do, while compulsion modals express what an agent cannot but do. Ascriptions of ability modals are relevant to understanding the moves the Prover and Skeptic can, or, are able to, make, and that ascriptions of compulsion modals are relevant to understanding what it means for the Skeptic to be in a position such that they cannot but accept the conclusion of an argument if they have accepted the premises and have no counter. Once the relevant ascriptions of abilities and their semantics are handled within the PSM, one can begin to think about the ability itself. Deductive reasoning is to be understood in terms of the powers or abilities of agents given their agential capacities, i.e. what they can prove to the other. This agential capacity for deduction will then be illustrated within the PSM. 

Chair: Ante Debeljuh

Time: 03 September, 14:00 – 14:30

Location: SR 1.007