I was recently interviewed by from the wonderfully engaging podcast In Limbo. Come listen to us chat about ontologies of disease, and how philosophers can work with life science researchers to coordinate data about the real world.
Santorio's Counterfactual Triviality Result
I recently presented a manuscript of Paolo Santorio's where he extends Lewis's well-known triviality results to counterfactual conditionals. Similar material was covered in Paolo and Justin Khoo's NASSLI course Probabilities of Conditionals and Conditional Probabilities. I essentially walk through the details in my presentation. If you're inclined to work through the details of proofs - to make sure they work - then you might enjoy this excursion here.
Moderate Modal Skepticism
Philosophers frequently motivate claims as possible based on conceivability.[1] It is then natural to wonder whether conceiving is a reliable method for generating justified beliefs in possibility claims. Yablo argued[2] conceiving proposition p as possible provides evidence that p is, in fact, possible.[3] Less optimistic philosophers, such as van Inwagen,[4] claim conceiving proposition p as possible provides no evidence that p is possible. If van Inwagen is correct, philosophical arguments relying on possibility claims motivated solely by conceivability are suspect. Given how widespread such philosophical arguments seem to be, van Inwagen’s claims are worth examining in detail.
In Section 1 of this paper, we extract and evaluate van Inwagen’s argument for Moderate Modal Skepticism, the view that while agents have justified beliefs in some – rather commonsensical – modal claims, agents do not have justified beliefs in many other – rather philosophical – modal claims. Having outlined van Inwagen’s position, in Section 2 we note a long-standing objection to van Inwagen’s argument – that it can be generalized to undermine justified beliefs in commonsensical modal claims as well as philosophical modal claims – fails, but a related worry – that van Inwagen’s argument relies on an under-motivated distinction between basic and non-basic modal claims – does not. Two responses are offered on behalf of van Inwagen, though neither are entirely satisfying. Additionally, we note van Inwagen’s argument implausibly requires agents justified in believing a given modal claim is true in every case know the modal claim is true. Having observed costs of van Inwagen’s characterization of the relationship between conceivability and possibility, in Section 3 we examine Yablo’s well-known alternative, which does not rely on an obscure distinction between basic and non-basic modal claims, and which allows justified belief and knowledge concerning modal propositions to come apart. Since there are independent reasons to prefer Yablo’s proposal to van Inwagen’s as an appropriate analysis of the link between conceivability and possibility, and since – pace van Inwagen – Yablo’s proposal does not entail Moderate Modal Skepticism, we conclude the various philosophical arguments targeted by van Inwagen are not threatened by his skeptical thesis.
[1](Putnam, 1980)’s super-Spartans; (Putnam, 1975)’s twin-earth; (Lewis, 1980)’s pained Martians; (Jackson, 1986)’s Mary; (Chalmers, 1996)’s zombies, etc.
[2]Cp. (Chalmers, 2002); others tie modal knowledge to counterfactual reasoning (Williamson, 2007), (Kroedel, 2017).
[3](Yablo, 1993).
[4](Van Inwagen, 1999).
Trust Logic, Not Tortoises
Carroll's note What Achilles Said to the Tortoise holds many lessons, many of which related to putative justification - or lack of justification - for basic logical inferences. Recently, Romina Padro, pulling from coursework and discussions with Kripke, has argued one more lesson should be added to the list, namely, that under certain conditions adopting basic logical inferences is impossible. I've a few thoughts on this new lesson, in particular how it might play with the old lessons. Check it out a recent draft here!
Curtis & Robson on the Metaphysics of Time
Benjamin Curtis and Jon Robson, in A Critical Introduction to the Metaphysics of Time, provide an impressive overview of contemporary debates over the nature of time. Check out a draft of my review of the book here.
Of the wealth of material covered in this introductory text, I found the authors' discussion of future contingents fascinating, and yet perplexing. In particular, the authors claim the possibility of an (alethically) open future conflicts with the classical logic principle of bivalence. They then use deviation from classical logic to undermine the possibility of future contingents. I take issue with several claims made by the authors (you can see a few more in the review above). For one, bivalence is intuitive, but it's not limited to classical logic. Other non-classical logics incorporate this principle as well. Of course, this pushes the question back from logical principles to logical theories. To be fair, the authors claim classical logic is widely accepted due to its theoretical virtues. But there is no discussion of what theoretical virtues are desirable and why, or comparison against alternative logics.
One might think my complaint is unfair, since this is an introduction to the metaphysics of time and not a philosophical logic text. I would, however, relate this same claim to the authors. If you're going to appeal to classical logic to undermine metaphysical theses, more discussion of why philosophers have accepted classical logic over others is desirable. Otherwise, leave philosophical logic questions alone and focus on the metaphysics.
Jason Turner's Factualism
Appearances to the contrary the world consists ultimately of facts, not of things. According to Factualism, familiar objects and properties of experience are mere abstractions from this single ontological category. Jason Turner’s recent defense of a version of this thesis in The Facts in Logical Space: A Tractarian Ontology, is precise, exhaustive, and persuasive. Those working on facts will find much of interest, as will those working at the intersection of formal logic and metaphysics...