How Strong Is a Counterfactual?

Abstract

The literature on counterfactuals is dominated by strict accounts (SA) and variably strict accounts (VSA). Counterexamples to the principle of Antecedent Strengthening were thought to be fatal to SA; but it has been shown that by adding dynamic resources to the view, such examples can be accounted for. We broaden the debate between VSA and SA by focusing on a new strengthening principle, Strengthening with a Possibility. We show dynamic SA classically validates this principle. We give a counterexample to it and show that extra dynamic resources cannot help SA. We then show VSA accounts for the counterexample if it allows for orderings on worlds that are not almost-connected, and that such an ordering naturally falls out of a Kratzerian ordering source semantics. We conclude that the failure of Strengthening with a Possibility tells strongly against Dynamic SA and in favor of an ordering source-based version of VSA.

Causal decision theory, context, and determinism

“…SeeLewis (1973aLewis ( , 1986Lewis ( , 2000.23 The contextualist view of similarity I sketch in this section has a lot in common with views espoused by, e.g.,Kaufmann (2004), Ippolito (2016,Khoo (2016),Boylan and Schultheis (2021), andDorr and Hawthorne (MS). It also has something in common with so-called causal modelling approaches to counterfactuals, like those ofHiddleston (2005),Santorio (2019),Gallow (2022), orKhoo (2022).…”

“…In particular, I'm not going to assume that these questions are always unanswered in a context. SeeBoylan and Schultheis (2021) for a similar understading of salient questions.…”