Online research in philosophy

We report two new phenomena of deontic reasoning: (1) For conditionals with deontic content such as, "If the nurse cleaned up the blood then she must have worn rubber gloves", reasoners make more modus tollens inferences (from "she did not wear rubber gloves" to "she did not clean up the blood") compared to conditionals with epistemic content. (2) For conditionals in the subjunctive mood with deontic content, such as, "If the nurse had cleaned up the blood then she must have had to wear rubber gloves", reasoners make the same frequency of all inferences as they do for conditionals in the indicative mood with deontic content. In this regard, subjunctive deontics are different from subjunctive epistemic conditionals: reasoners interpret subjunctive epistemic conditionals as counterfactual and they make more negative inferences such as modus tollens from them. The experiments show these two phenomena occur for deontic conditionals that contain the modal auxiliary "must" and ones that do not. We discuss the results in terms of the mental representations of deontic conditionals and of counterfactual conditionals.

1. Plot ...................................................................................................................................... 1 2. What Kind of Modal? .......................................................................................................... 4 3. if-Clauses ............................................................................................................................. 6 3.1. Digression: Methods of Unification ............................................................................. 8 4. Bare Conditionals ................................................................................................................ 9 4.1. Digression: “will” as a modal? ................................................................................... 11 5. Licensing the Morphology ................................................................................................ 13 6. Embedded Bare Conditionals ............................................................................................ 15 7. Features in Subjunctive Conditionals ................................................................................ 18 8. Appendix 1: Feature Survey .............................................................................................. 22 9. Appendix 2: Semantics ...................................................................................................... 23 References ................................................................................................................................ 24.

Subjunctive conditionals are fundamental to rational decision both in single agent and multiple agent decision problems. They need explicit analysis only when they cause problems, as they do in recent discussions of rationality in extensive form games. This paper examines subjunctive conditionals in the theory of games using a strict revealed preference interpretation of utility. Two very different models of games are investigated, the classical model and the limits of reality model. In the classical model the logic of backward induction is valid, but it does not use subjunctive conditionals; the relevant subjunctive conditionals do not even make sense. In the limits of reality model the subjunctive conditionals do make sense but backward induction is valid only under special assumptions.

Subjunctive conditionals have their uses, but constituting the meaning of dispositional predicates is not one of them. More germane is the analysis of dispositions in terms of "bases"--except that past efforts to maintain an ontic gap between dispositions and their bases, while not wholly misguided, have failed to appreciate the semantic birthright of dispositional concepts as a species of theoretical construct in primitive science.

This paper presents a new theory of the truth conditions for indicative conditionals. The theory allows us to give a fairly unified account of the semantics for indicative and subjunctive conditionals, though there remains a distinction between the two classes. Put simply, the idea behind the theory is that the distinction between the indicative and the subjunctive parallels the distinction between the necessary and the a priori. Since that distinction is best understood formally using the resources of two-dimensional modal logic, those resources will be brought to bear on the logic of conditionals.

The goal of this paper is to offer a compositional semantics for subjunctive and indicative will conditionals, and to derive the projection properties of the types of conditionals we consider and in particular those of counterfactual conditionals. It is argued that subjunctive conditionals are "bare" conditional embedded under temporal and aspectural operators, which constrain the interpretation of the modal operators in the embedded conditional. Furthermore, it is argued that a theory of presupposition projection à la Heim together with the present proposal about their logical form explains the projection facts.

Attempts to capture the distinction between categorical and dispositional states in terms of more primitive modal notions – subjunctive conditionals, causal roles, or combinatorial principles – are bound to fail. Such failure is ensured by a deep symmetry in the ways dispositional and categorical states alike carry modal import. But the categorical/dispositional distinction should not be abandoned; it underpins important metaphysical disputes. Rather, it should be taken as a primitive, after which the doomed attempts at reductive explanation can be transformed into circular but interesting accounts.

Conventional wisdom has it that many intriguing features of indicative conditionals aren’t shared by subjunctive conditionals. Subjunctive morphology is common in discussions of wishes and wants, however, and conditionals are commonly used in such discussions as well. As a result such discussions are a good place to look for subjunctive conditionals that exhibit features usually associated with indicatives alone. Here I offer subjunctive versions of J. L. Austin’s ‘biscuit’ conditionals—e.g., “There are biscuits on the sideboard if you want them”—and subjunctive versions of Allan Gibbard’s ‘stand-off’ or ‘Sly Pete’ conditionals, in which speakers with no relevant false beliefs can in the same context felicitously assert conditionals with the same antecedents and contradictory consequents. My cases undercut views according to which the indicative/subjunctive divide marks a great difference in the meaning of conditionals. They also make trouble for treatments of indicative conditionals that cannot readily be generalized to subjunctives.

This paper presents a new theory of the truth conditions for indicative conditionals. The theory allows us to give a fairly unified account of the semantics for indicative and subjunctive conditionals, though there remains a distinction between the two classes. Put simply, the idea behind the theory is that the distinction between the indicative and the subjunctive parallels the distinction between the necessary and the a priori. Since that distinction is best understood formally using the resources of two-dimensional modal logic, those resources will be brought to bear on the logic of conditionals.