Abstract
In all cases, the problem concerns the proper meaning of subjunctive and counterfactual conditionals. For present purposes, a conditional sentence is one composed of at least two clauses, the central connective of which is, or is understood to be, "if... then." A subjunctive conditional is a conditional sentence in which the clause following the "if," the antecedent, may be true or false, but in which the truth or falsity of the entire sentence does not depend upon the truth or falsity of its two clauses, the antecedent and consequent. A contrary-to-fact conditional, or counterfactual sentence, is a subjunctive conditional sentence which implicitly asserts that the antecedent is false. An example of the subjunctive conditional is