The Basic Analysis of Subjunctive Conditionals

Abstract

Having laid the groundwork, we can now attempt to construct an analysis of subjunctive conditionals. The basic tool for this analysis is provided by Theorem 3.11 of Chapter I. According to that theorem, a subjunctive conditional ⌜(P > Q)⌝is true iff Q is true in every possible world that might be actual if Pwere true. That is, assuming the Generalized Consequence Principle, we have:

• 1.1 ⌜(P>Q)⌝is true in the actual world iff for every possible world a, if αMP⌝ then Q is true in α; ⌜QMP⌝ is true iff for some α such that αMP, Q is true in α

This is not yet a philosophically satisfactory definition of the simple subjunctive, because the relation M was defined in terms of ‘>‘, but if we can provide an alternative analysis of M, principle 1.1 will constitute an analysis of ‘>‘. That will be our strategy here. Let us say that a is a P-worldwhen αMP.¹Thus our task is to analyze the notion of a P-world.