Wolfgang Schwarz

Noncognitivism, 'ought', and uncertainty

Suppose there are no objective moral facts. It's tempting to think that this calls for a special semantics for moral language. Perhaps moral statements somehow express moral attitudes rather than describe the world. The trouble is that moral statements seem to behave like ordinary descriptive statements. Not only can we freely conjoin moral and descriptive statements. We can even use the same words – say, 'you ought to leave' – to express a moral attitude but also to report the implications of some contextually salient norms. It would be nice if we could use a standard descriptivist semantics for 'ought' statements even if we don't believe in objective normative facts.

An RSA model of free choice

Let's continue. I'm going to present a new (?) model of free choice. Free choice is the phenomenon that a disjunction embedded in a possibility modal conveys the possibility of both disjuncts. 'You may have tea or coffee', for example, conveys that you may have tea and you may have coffee. Champollion, Alsop, and Grosu (2019) present an RSA model of this effect, drawing on the "lexical uncertainty" account from Bergen, Levy, and Goodman (2016). I'll present a model that does not rely on lexical uncertainty.

The independence of free choice alternatives

It is well-known that disjunctive possibility and necessity statements appear to imply the possibility of the disjuncts:

(FC) \( \Diamond(p \lor q) \Rightarrow \Diamond p \land \Diamond q \).
(RP) \( \Box(p \lor q) \Rightarrow \Diamond p \land \Diamond q \).

The first kind of inference is known as a "free choice" inference, the second is "Ross's Paradox".

For example, (1a) seems to imply (1b) and (1c):

(1a) Alice might [or: must] have gone to the party or to the concert.
(1b) Alice might have gone to the party.
(1c) Alice might have gone to the concert.

In chapter 3 of his dissertation, Booth (2022), Richard Booth points out that (FC) and (RP) underdescribe the true effect.

Cariani on the modal future

I've been reading Fabrizio Cariani's The Modal Future (Cariani (2021)). It's great. I have a few comments.

This book is about the function of expressions like 'will' or 'gonna' that are typically used to talk about the future, as in (1).

(1) I will write the report.

Intuitively, (1) states that a certain kind of writing event takes place – but not right here and now. 'Will' is a displacement operator, shifting the point of evaluation. Where exactly does the writing event have to take place in order for (1) to be true?

Here's a natural first idea. (1) is true as long as a relevant writing event takes place at some point in the future. This yields the standard analysis of 'will' in tense logic:

Mackay on counterfactual epistemic scenarios

An interesting new paper by David Mackay, Mackay (2022), raises a challenge to popular ideas about the semantics of modals. Mackay presents some data that look incompatible with classical two-dimensional semantics. But the data nicely fit classical two-dimensionalism, if we combine that with a flexible form of counterpart semantics.

Before I discuss the data, here's a reminder of some differences between epistemic modals and non-epistemic ("metaphysical") modals.

Ability, control, and chance

In my paper "Ability and Possibility", I argued that ability statements should be analysed as simple possibility modals: 'S can phi' is true iff S phis at some world compatible with relevant circumstances.

This view is widely considered inadequate because it seems to violate two (related) intuitions about ability.

One is that ability requires a kind of robustness: if you have the ability to phi, then you reliably phi whenever the need arises, under a variety of circumstances.

Epistemic counterparts 7: Distributed plural roles

So far, we have looked at cases in which an agent has a descriptive belief (e.g., "the creature approaching through the woods is a bear"), which gets reported as a singular belief ("Mary beliefs Mark is a bear"). But sometimes we attribute singular beliefs even though the subject appears to have only a general (quantified) attitude about the relevant individual.

A murder has been committed. The detective has figured out that the culprit probably comes from a certain mountain village. She knows little about that village, but believes that all its inhabitants are poor peasants. You are one of the villagers. We might say:

Epistemic counterparts 6: De re/de dicto equivalence

Compare the following three sentences.

(1) I thought my husband was a bear.
(2) Mary thinks her husband is a bear.
(3) I think my husband is a bear.

(1) and (2) are ambiguous between a "de re" reading and a "de dicto" reading. But (3) only seems to have the "de dicto" reading. How come?

According to the semantics I have described in earlier parts of this series, an utterance of (3) is true on its de re reading iff (roughly) there is a suitable role R such that (i) in all the speaker's belief worlds, whatever plays R is a bear, and (ii) in the actual world, the speaker's husband plays R.

Epistemic counterparts 5: Coincident roles and shifted beliefs

In the previous post, I have assumed that conversational context somehow determines a unique "suitable role" for each individual under discussion, relative to every epistemic subject. This is an unrealistic assumption.

For example, I believe that Canberra gets cold in winter. But Canberra is known to me as the occupant of many roles. Among other things, I know it as the capital of Australia, as the city in which I lived for most of 2012, and as the destination of my most recent international trip. When I say that I know (or believe) that Canberra gets cold, none of these roles may be particularly salient.

Epistemic counterparts 4: Truth-conditions (first stab)

In this post, I'm going to present a first stab of a formal semantics for de re belief reports.

As I explained in the last post, I'm going to assume that for every epistemic subject at every time there is a set of doxastically accessible worlds, representing how the subject takes the world to be. I will sometimes refer to these worlds as the subject's 'belief worlds'.

On that background, we can make the guiding idea behind the Quine-Kaplan model more precise: 'S believes that x is F' is true iff there is a suitable role R such that (1) in all worlds doxastically accessible for S, whatever plays R is F, and (2) in the actual world, x plays R.

Epistemic Counterparts 3: Possible-worlds models

This is part 3 of a series on epistemic counterpart semantics (part 1, part 2).

Recall the guiding idea: A de re report 'S believes that x is F' is true iff there is a suitable role R such that (1) S believes that whatever plays R is F, and (2) in fact, x plays R.

I said that these truth-conditions naturally emerge if we treat 'believes' as a modal, quantifying over a set of accessible worlds. So I am going to assume that for any relevant subject in any relevant situation there is a set of "doxastically accessible" worlds which somehow characterise what the subject believes. I want to say a few words to clarify this assumption.

Epistemic Counterparts 2: Acquaintance, files, and suitable roles

This is part 2 of a series on epistemic counterpart semantics. Part 1 is here.

I want to defend what I called the "Quine-Kaplan model" of de re belief ascriptions. According to this model, 'S believes that x is F' is true iff there is a suitable role R such that (1) S believes that whatever plays R is F, and (2) in fact, x plays R.

In this post, I mainly want to explain what I mean by a "suitable role". This will also bring to light some arguments in favour of the Quine-Kaplan model.

Epistemic counterpart semantics

I have decided to write a series of posts on epistemic applications of counterpart semantics, mostly to organise my own thoughts.

Let's start with a motivating example, from Sæbø 2015.

On September 14 2006, Mary Beth Harshbarger shot her husband, whom she had mistaken for a bear. At the trial, she "steadily maintained that she thought her husband was a black bear", as you can read on Wikipedia.

Discourse, Diversity, and Free Choice

Another paper: "Discourse, Diversity, and Free Choice" has come out at the AJP.

This paper began as a couple of blog posts in January 2007, here and here. At the time, I was thinking about why counterfactuals with unspecific antecedents appear to imply counterfactuals with more specific antecedents. I noticed that a similar puzzle arises for possibility modals in general. My hunch was that this is a special kind of scalar implicature: if you say of a group of things (say, rooms) that they satisfy an unspecific predicate (like, having a size between 10 and 20 sqm), you implicate that different, more specific predicates, apply to different memebers of the group.

Strengthening the prejacent

Sometimes, when we say that someone can (or cannot, or must, or must not) do P, we really mean that they can (cannot, must, must not) do Q, where Q is logically stronger than P. By what linguistic mechanism does this strengthening come about?

Example 1. My left arm is paralysed. 'I can't lift my (left) arm any more', I tell my doctor. In fact, though, I can lift the arm, in the way I can lift a cup: by grabbing it with the other arm. When I say that I can't lift my left arm, I mean that I can't lift the arm actively, using the muscles in the arm. I said that I can't do P, but what I meant is that I can't do Q, where Q is logically stronger than P.

Should you rescue the miners?

Many accounts of deontic modals that have been developed in response to the miners puzzle have a flaw that I think hasn't been pointed out yet: they falsely predict that you ought to rescue all the miners.

The miners puzzle goes as follows.

Ten miners are trapped in a shaft and threatened by rising water. You don't know whether the miners are in shaft A or in shaft B. You can block the water from entering one shaft, but you can't block both. If you block the correct shaft, all ten will survive. If you block the wrong shaft, all of them will die. If you do nothing, one miner will die.

Let's assume that the right choice in your state of uncertainty is to do nothing. In that sense, then, (1) is true.

Owned possibility and unowned ability

Superficially, modal auxiliaries such as 'must', 'may', 'might', or 'can' seem to be predicate operators. So it is tempting to interpret them as functions from properties to properties: just as 'Alice jumps' attributes to Alice the property of jumping, 'Alice can jump' attributes to her the property of being able to jump, 'Alice may jump' attributes the property of being allowed to jump, and so on.

Perhaps the biggest obstacle to this approach comes from quantified constructions. If 'Alice may jump' attributes to Alice the property of being allowed to jump, then 'one of us may jump' should say that one of us has the property of being allowed to jump. But while this is one possible reading of the sentence, 'one of us may jump' also has a reading on which it states that it is permissible that one of us jumps. There is a kind of de re/de dicto ambiguity here, which suggests that 'may' can not only apply to properties but also to propositions.

Diamond Implicature II

I've thought a little more about this thing I called 'diamond implicature', and I've come up with the following explanation. I don't know if it's original, and unfortunately, I don't see how exactly it applies to the antecedent of counterfactuals, which is what I am most interested in.

The explanandum is that in many contexts, appears to imply . For example,

Diamond implicature

If I say "", you would often take me to have asserted both "" and "". A quick internet search didn't come up with any useful literature on this, so I'd be grateful for pointers.