A solution to Karttunen's Problem

There is a difference between the conditions in which one can felicitously assert a ‘must’-claim versus those in which one can use the corresponding non-modal claim. But it is difficult to pin down just what this difference amounts to. And it is even harder to account for this difference, since assertions of 'Must ϕ' and assertions of ϕ alone seem to have the same basic goal: namely, coming to agreement that [[ϕ]] is true. In this paper I take on this puzzle, known as Karttunen’s Problem. I begin by arguing that a ‘must’-claim is felicitous only if there is a shared argument for its prejacent. I then argue that this generalization, which I call Support, can explain the more familiar generalization that ‘must’-claims are felicitous only if the speaker’s evidence for them is in some sense indirect. Finally, I sketch a pragmatic derivation of Support

If P, Then P!

The Identity principle says that conditionals with the form 'If p, then p' are logical truths. Identity is overwhelmingly plausible, and has rarely been explicitly challenged. But a wide range of conditionals nonetheless invalidate it. I explain the problem, and argue that the culprit is the principle known as Import-Export, which we must thus reject. I then explore how we can reject Import-Export in a way that still makes sense of the intuitions that support it, arguing that the differences between indicative and subjunctive conditionals play a key role in solving this puzzle

A Counterexample to Modus Ponenses

McGee 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 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

The case of the missing ‘If’: Accessibility relations in Stalnaker’s theory of conditionals

A part of Stalnaker (1968)’s influential theory of conditionals has been neglected, namely the role for an accessibility relation between worlds. I argue that the accessibility relation does not play the role intended for it in the theory as stated, and propose a minimal revision which solves the problem, and brings the theory in line with the formulation in Stalnaker & Thomason 1970

Dissatisfaction Theory

I propose a new theory of semantic presupposition, which I call dissatisfaction theory. I first briefly review a cluster of problems − known collectively as the proviso problem − for most extant theories of presupposition, arguing that the main pragmatic response to them faces a serious challenge. I avoid these problems by adopting two changes in perspective on presupposition. First, I propose a theory of projection according to which presuppositions project unless they are locally entailed. Second, I reject the standard assumption that presuppositions are contents which must be entailed by the input context; instead, I propose that presuppositions are contents which are marked as backgrounded. I show that, together, these commitments allow us to avoid the proviso problem altogether, and generally make plausible predictions about presupposition projection out of connectives and attitude predicates. I close by sketching a two-dimensional implementation of my theory which allows us to make further welcome predictions about attitude predicates and quantifiers

Import‐Export and ‘And’

Import-Export says that a conditional 'If p, if q, r' is always equivalent to the conditional 'If p and q, r'. I argue that Import-Export does not sit well with a classical approach to conjunction: given some plausible and widely accepted principles about conditionals, Import-Export together with classical conjunction leads to absurd consequences. My main goal is to draw out these surprising connections. In concluding I argue that the right response is to reject Import-Export and adopt instead a limited version which better fits natural language data; accounts for all the intuitions that motivate Import-Export in the first place; and fits better with a classical conjunction

Talking about worlds

I explore the logic of the conditional, using credence judgments to argue against Duality and in favor of Conditional Excluded Middle. I then explore how to give a theory of the conditional which validates the latter and not the former, developing a variant on Kratzer (1981)'s restrictor theory, as well as a proposal which combines Stalnaker (1968)'s theory of the conditional with the theory of epistemic modals I develop in Mandelkern 2019a. I argue that the latter approach fits naturally with a conception of conditionals as referential devices which allow us to talk about particular worlds

Eavesdropping: What is it good for?

Eavesdropping judgments (judgments about truth, retraction, and consistency across contexts) about epistemic modals have been used in recent years to argue for a radical thesis: that truth is assessment-relative. We argue that judgments for 'I think that p' pattern in strikingly similar ways to judgments for 'Might p' and 'Probably p'. We argue for this by replicating three major experiments involving the latter and adding a condition with the form 'I think that p', showing that subjects respond in the same way to 'thinks' as to modals. This poses a serious challenge to relativist treatments of the modal judgments, since a relativist treatment of the corresponding 'thinks' judgments is totally implausible, so if a unified account of the phenomena is to be found, it cannot be a relativist one. We briefly sketch how a unified account might look

Hurford Conditionals

Compare the following conditionals: 'If John is not in Paris, he is in France' versus 'If John is in France, he is not in Paris.' The second sounds entirely natural, whereas the first sounds quite strange. This contrast is puzzling, because these two conditionals have the same structure at a certain level of logical abstraction, namely 'If ¬p+, then p.' We argue that existing theories of informational oddness do not distinguish between these conditionals. We do not have an account of the divergence in judgments about the two, but we think this is a fascinating puzzle which we pose here in the hope others will be able to solve it

Against Preservation

Bradley offers a quick and convincing argument that no Boolean semantic theory for conditionals can validate a very natural principle concerning the relationship between credences and conditionals. We argue that Bradley’s principle, Preservation, is, in fact, invalid; its appeal arises from the validity of a nearby, but distinct, principle, which we call Local Preservation, and which Boolean semantic theories can non-trivially validate