The Art of the Possible

The chapter provides an examination of competing accounts of truthmakers for judgments concerning contingency, necessity, possibility, and for counterfactual and subjunctive conditionals. On the one side are the ‘Humeans’ who see the universe as modally bereft, in David Lewis’ words, it is ‘just one little thing and then another’. Lewis’ account of modal discourse posits myriad alternative universes. Modal judgments are recast as judgments concerning similarities. The resulting picture is found to make contingencies hard to come by: necessities, not contingencies, rule. An Aristotelian universe, in contrast, would be populated by interacting objects, and would appear to provide ample truthmakers for modal judgments. This impression does not survive scrutiny, however. Humeans and Aristotelians alike are obliged to reconstrue modal discourse in a way that reflects pressures arising in the manifest image, but leaves the modal texture of reality untouched.

Counterfactuals and Probability

Dorothy Edgington has been a resolute defender of an NTV account of conditionals, according to which a conditional does not express a proposition that makes a categorical claim about the world, but instead make a qualified claim, or express a conditional belief, qualified by or conditional on the proposition expressed by the antecedent. Unlike some philosophers who defend an NTV view for indicative conditionals, but not for subjunctive or counterfactual conditionals, Edgington argues for the more radical thesis that both kinds of conditionals should be given a non-propositional analysis. This chapter considers Edgington’s NTV account of subjunctive conditionals, the role of objective probability in the account, and its relation to the possible-worlds propositional analysis of subjunctive conditionals.

Conditional Reasoning Part II

The influential idea that the Ramsey test provides a proper analysis of the psychological means by which we evaluate indicative and subjunctive conditionals is explained. Several recent views have implicated sui generis imaginative states in the psychological implementation of the Ramsey test. The comparative relevance of the Ramsey test to indicative and subjunctive conditionals is explained. It is then argued that one can accept the basic insight afforded by the Ramsey test without concluding that sui generis imaginative states are used in conditional reasoning. A simpler, more parsimonious approach involves only beliefs. Anyone who could have used sui generis imaginative states to arrive at a belief in a new conditional via the Ramsey test could have, with equal warrant, inferred the conditional from their standing beliefs. Finally, it is shown how the imaginings that occur in response to philosophical thought experiments can in fact be sequences of beliefs.

A Counterexample to Modus Ponenses

McGee (1985) argued that modus ponens was invalid for the natural language conditional ‘If…then…’. Many subsequent responses have argued that, while McGee’s examples show that modus ponens fails to preserve truth, they do not show that modus ponens fails to preserve rational full acceptance, and thus modus ponens may still be valid in the latter informational sense. I show that when we turn our attention from indicative conditionals (the focus of most of the literature to date) to subjunctive conditionals, we find that modus ponens does not preserve either truth or rational full acceptance, and thus is not valid in either sense. In concluding I briefly consider how we can account for these facts.

Conditional Propositions and Conditional Assertions

A comparison of accounts of indicative conditional statements that treat them as a distinctive kind of conditional speech act—qualified assertion of the consequent qualified by the supposition of the antecedent—and accounts that treat them as unqualified assertions of propositions that are a function of antecedent and consequent. The aim is to reconcile the two accounts by making them precise in a common pragmatic framework, and showing that the former can be seen to be equivalent to a limiting case of the latter. It is argued that this way of representing the conditional assertion account helps to explain the relation between indicative and subjunctive conditionals.

Knowledge and Conditionals

A set of interconnected chapters on topics in the theory of knowledge. Part 1 considers the concept of knowledge, its logical properties, and its relation to belief and partial belief, or credence. It includes a discussion of belief revision, two discussions of reflection principles, a chapter about the status of self-locating knowledge and belief, a chapter about the evaluation of normative principles of inductive reasoning, and a development and defense of a contextualist account of knowledge. Part 2 is concerned with conditional propositions, and conditional reasoning, with chapters on the logic and formal semantics of conditionals, a discussion of the relation between indicative and subjunctive conditionals and of the question whether indicative conditionals express propositions, a chapter considering the relation between counterfactual propositions and objective chance, a critique of an attempt to give a metaphysical reduction of counterfactual propositions to nonconditional matters of fact, and a discussion of dispositional properties, and of a dispositional theory of chance.

Hyperfactuals

A historical sequence is said to be hyperfactual whenever it contains facts that have been proved to exist twice, that is, they exist under two alternative courses of events: the factual and the counterfactual. In such cases, we may verify whether multiple courses of action lead to the same outcome. Drawing upon an idea from Nelson Goodman, each section of this article highlights a different type of hyperfactual sequence: those resulting from the turbulence of historical turning points; those resulting from long term historical sequences; and those resulting from competing courses of action. The final section conveys how hyperfactuals represent the resistance of the multiple layers of history to the formalism of subjunctive conditionals.