Research

Conversational Exculpature

Conversational Exculpature (Girl with the Unicorn)

In addition to conversational implicature, there is also such a thing as conversational exculpature, a pragmatic process whereby information is subtracted from, rather than added to, what the speaker literally says. This pragmatic content subtraction explains why we can say “Rob is six feet tall” without implying that Rob is between 5’11.99” and 6’0.01” tall, and why we can say “Ellen has a hat like the one Sherlock Holmes always wears” without implying Holmes exists or has a hat. I have a simple formalism for understanding this pragmatic mechanism, specifying how, in context, the result of subtracting one piece of information from another is determined. A distinctive feature of this approach is the crucial role played by the question under discussion in determining the result of a given exculpature

The resulting theory of exculpature has both linguistic and philosophical interest. It can help us understand a wide range of linguistic phenomena, such as loose talk, certain kinds of metaphor, Hob-Nob anaphora, and the rigidification of definite descriptions. And by explaining how reference to fictional entities and scenarios can facilitate our description of the world, it casts new light on a range of old philosophical issues, including problems about fictional characters, mathematical ontology, and Frege’s puzzle.

Inquisitive Decision Theory

Inquisitive Decision Theory (Oedipus and the Sphinx) Choices confront agents with questions. Lost in the forest and coming to a fork in the road, you wonder Which path will get me out of here? Plotting your next chess move, you are confronted with the question How do I put my opponent on the defensive? The choice of how many eggs to buy at the supermarket raises the question How many eggs go into a spaghetti carbonara for four? And so on: whenever you make a choice, you face a question. And what you decide to do normally depends on your answer to the question raised. Take the supermarket situation. If you reckon you need five eggs for your carbonara, you will buy half a dozen. If you think you need eight, you get a dozen. If you are unsure, maybe you still get a dozen just to be on the safe side. Thus your choice is guided by your answer to the question it confronted you with.

Inquisitive decision theory is a systematic treatment of this question-centric way of thinking about decision-making. It can account for many ordinary patterns of behaviour that classical decision theory does not capture. In particular, it can account for the distinction between recognition and recall, and for the behaviour of agents whose beliefs are inconsistent, or not closed under entailment. The theory builds on a converging set of insights about the role of questions from epistemology and the philosophy of language, semantics, pragmatics, cognitive science and the metaphysics of propositions.

On the inquisitive account of beliefs, an agent’s beliefs are not perfectly integrated, as in Hintakka-style models of belief. But neither are they partitioned into isolated fragments, as in fragmentation theories. Rather, beliefs cohere only insofar as they are thematically linked. Thus an agent’s beliefs are linked together in a complex structure that is best described as a web. Some beliefs in the web may be closely integrated, while others are so loosely connected that they can vary independently of one another.

Newton’s First Law of Motion 🍎

I argue that an early, unauthorised mistranslation led to a misunderstanding about the content of Newton’s First Law of Motion that has beguiled many scholars and physicists until the present day. The First Law is standardly understood as a principle about force-free bodies, stating that such bodies persist in their state of rest or uniform motion in a straight line. But a careful reading of the text shows the First Law to be a stronger, more general principle, to the effect that changes in any body’s state of motion are compelled by an impressed force –– whether or not that body is subject to forces.

Chance and the Continuum Hypothesis

There is a connection between objective chance and the size of the continuum. When you spin a roulette wheel, or flip infinitely many random coins, you pick out a point from a continuum at random. Here are three claims about the chance distribution of such processes:

  1. No individual point has a positive chance of being picked out.
  2. Every proposition about the outcome of the process has a particular chance of coming true.
  3. Chances are countably additive.

These claims are consistent with standard set theory (ZFC), and I argue we have excellent reason to think they are all true. In 1930, Stanislaw Ulam proved a theorem showing that it follows from this and the axioms of ZFC that there are many cardinalities between countable infinity and the cardinality of the continuum. So the continuum hypothesis is false.

Divergent Supertasks

In this note, I muse on a thought experiment by Øystein Linnebo (2020) involving an infinite scale, pausing along the way to contemplate an infinitely jittery flee, an infinitely complex border swap and an infinitely electric glass rod. Linnebo argues that, if it were possible to apply an infinite positive weight and an infinite negative weight to a working scale, the resulting net weight could end up being any real number, depending on the procedure by which these weights are applied. Appealing to the First Postulate of Archimedes’ treatise on balance, I argue instead that the scale would always read 0 kg.

Selected Commentaries

Slides and Handouts

The Atlas or the Web? (University of Toronto)
Loose Talk, Pragmatic Slack, and a Little Bit of Metaphor, slides and handout (VTLx Speaker series, Virginia Tech)
Questions in Action, slides and handout (Pittsburgh philosophy)
Flipping coins, Spinning Tops and the Continuum Hypothesis (Washington Square Circle, NYU)
Loose Talk and the Pragmatics of Anti-Realism (Pragmasophia: 2nd International Conference on Pragmatics and Philosophy)
Formal Pragmatics and Conversational Exculpature (A class for Stephen Schiffer’s Advanced Introduction to the Philosophy of Language)
Veracity Exculpature vs Literary Indirect Discourse (Philippe Schlenker’s Foundational Issues in Semantics seminar)
In Defense of the Romance of Mathematics. (CRAC Psychology Lab, Paris 8)
Mathematics as a metaphor (Graham Priest’s Logic and Metaphysics Workshop)
Fregean Judgment slides (Haim Gaifman’s Frege seminar)
The Presuppositions Cheat Sheet

Shelter
Here are some classic papers by others that are otherwise difficult to obtain online:
Stalnaker’s “Propositions” (1976)
An early defense of Stalnaker’s views on propositions with critical comments from Larry Powers; in a volume of contributions to the 1972 Oberlin Colloquium in Philosophy, edited by Alfred MacKay and Daniel Merrill.
Hartry Field and Stephen Schiffer on Stalnaker on Intentionality
With a reply from Stalnaker; this is the April 1986 issue of the Pacific Philosophical Quarterly; thanks to Stephen for lending me his copy.
John Bell’s “How to teach Special Relativity”
Originally published in 1976 in Progress in Scientific Culture 1.2.
Robert Nozick’s “Counterfactuals and Two Principles of Choice”
Originally published in 1969 in Essays in Honor of Carl G. Hempel, edited by Nicholas Rescher.
Gibbard and Harper’s “Counterfactuals and Two Kinds of Expected Utility”
Including Stalnaker’s letter to Lewis, originally published in 1981 in Ifs: Conditionals, Belief, Decision, Chance, and Time, edited by William Harper, Robert Stalnaker and Glenn Pearce.
Claud Shannon’s “The Fourth-Dimensional Twist; or, A Modest Proposal in Aid of the American Driver in England”
Written in 1978 at All Soul’s in Oxford.
Schopenhauer’s ‘Preface to a [proposed] Translation of Hume’s Work’
A masterpiece of irony; Schopenhauer never found an editor interested in funding the translation project. The translation is from Patrick Bridgewater, Arthur Schopenhauer’s English Schooling. Routledge 1988.