The Evidential Conditional

Abstract

This paper outlines an account of conditionals, the evidential account, which rests on the idea that a conditional is true just in case its antecedent supports its consequent. As we will show, the evidential account exhibits some distinctive logical features that deserve careful consideration. On the one hand, it departs from the material reading of ‘if then’ exactly in the way we would like it to depart from that reading. On the other, it significantly differs from the non-material accounts which hinge on the Ramsey Test, advocated by Adams, Stalnaker, Lewis, and others.

Williamson on indicatives and suppositional heuristics

“…It may be, then, that our 'primary way of prospectively assessing conditionals' is not quite the Suppositional Procedure but rather some fixing of the Procedure, which adds to it some constraint linking antecedent and consequent: in order for us to accept 'If A, then C', it is necessary but not sufficient that we accept C on the supposition A; in addition, the supposition must, in some sense, make a relevant difference for the truth or likelihood of C. One would need to make precise the notion of a conditional antecedent 'making a relevant difference' for its consequent. Relevance for conditionals, however, is one of the most elusive concepts, and very different treatments of it have been proposed: (non-classical) logical, as in relevant logics (Dunn and Restall 2002); probabilistic-evidential (Douven 2016); based on default-and-penalty hypotheses (Skovgaard-Olsen et al, 2016); on causal connectedness (Schulz and van Rooij 2019); on evidential support (Crupi and Iacona 2020); on coherence relations between discourse clauses (Lassiter 2021); or on yet other notions. How to fix the Suppositional Procedure to take relevance into account seems to be an open issue.…”

Local Explanations via Necessity and Sufficiency: Unifying Theory and Practice

“…4. Counterintuitive implications of contrapositive relations abound, most famously in confirmation theory's raven paradox (Good, 1960;Hempel, 1945;Mackie, 1963), but also in the literature on natural language conditionals (Crupi & Iacona, 2020;Gomes, 2019;Stalnaker, 1981). Our formal framework aims to preserve intuition while extinguishing any potential ambiguity.…”

Three Ways of Being Non-Material

“…2 One might wonder whether a similar comparison can be carried out by relying on a modal semantics, given that there are modal treatments of the suppositional interpretation, and that the strict interpretation is naturally understood in modal terms. The modal semantics provided in [10] shows that such discussion is possible, although it will not be pursued here. Raidl, Iacona and Crupi [32] provides a completeness result in the modal framework for the logic of the evidential conditional.…”

“… Rott [34, p. 7], takes the failure of RW to be the hallmark of "difference-making conditionals". Crupi and Iacona[10] provides a more detailed discussion of RW.…”