In a time when conservatives believe that the traditional family is under increasing fire, some think an appeal to Darwinian science may be the answer. I argue that these conservatives are wrong to maintain that Darwinian theory can serve as the intellectual foundation for the traditional conception of the family. Contra Larry Arnhart and James Q. Wilson, a Darwinian philosophy of nature simply lacks the stability the traditional family requires; it cannot support the traditional conception of human nature and the (...) normativity it was thought to contain. If conservatives are to maintain these traditional ideas, the theoretical foundation must lie elsewhere. (shrink)

What is the role of affect in moral epistemology? Sentimentalists assert that moral knowledge is rooted in knowledge of specific situational moral truths, which affect is a necessary means for attaining. Rationalists claim moral knowledge is rooted in moral principles, knowledge of which is acquired a priori through reason alone; affect is unnecessary. Note that in this way of framing the debate, the issue concerns solely moral knowledge. Recent epistemology, however, has also highlighted the importance of understanding as an epistemic (...) good separate from knowledge. As such, moral understanding might have value over and above mere moral knowledge. Some philosophers have pointed to the importance moral understanding possesses for reliably doing the right thing, justifying yourself to others, developing virtue, and performing morally worthy action. In this paper, I argue that the sentimentalist account of understanding both specific moral truths and moral principles has significant advantages over, and can ground, the rationalist alternative. (shrink)

Consider the set of inferences that are acceptable to use in all our theory building endeavors. Call this set of inferences the universal theory building toolkit, or just ’the toolkit’ for short. It is clear that the toolkit is tightly connected to logic in a variety of ways. Beall, for example, has argued that logic just is the toolkit. This paper avoids making a stand on that issue and instead investigates reasons for thinking that, logic or not, the toolkit is (...) substructural. It is presented as a dialogue for the simple reason that it summarizes a range of dialogues on this subject that the author has had with various folks over the past few years. The method I use to investigate the toolkit is inspired in both philosophical and technical details by Alasdair Urquhart’s work on semantics for relevance logics from the early 1970s. (shrink)

We live in a world of crowds and corporations, artworks and artifacts, legislatures and languages, money and markets. These are all social objects — they are made, at least in part, by people and by communities. But what exactly are these things? How are they made, and what is the role of people in making them? In The Ant Trap, Brian Epstein rewrites our understanding of the nature of the social world and the foundations of the social sciences. Epstein (...) explains and challenges the three prevailing traditions about how the social world is made. One tradition takes the social world to be built out of people, much as traffic is built out of cars. A second tradition also takes people to be the building blocks of the social world, but focuses on thoughts and attitudes we have toward one another. And a third tradition takes the social world to be a collective projection onto the physical world. Epstein shows that these share critical flaws. Most fundamentally, all three traditions overestimate the role of people in building the social world: they are overly anthropocentric. Epstein starts from scratch, bringing the resources of contemporary metaphysics to bear. In the place of traditional theories, he introduces a model based on a new distinction between the grounds and the anchors of social facts. Epstein illustrates the model with a study of the nature of law, and shows how to interpret the prevailing traditions about the social world. Then he turns to social groups, and to what it means for a group to take an action or have an intention. Contrary to the overwhelming consensus, these often depend on more than the actions and intentions of group members. (shrink)

Relevant logics infamously have the property that they only validate a conditional when some propositional variable is shared between its antecedent and consequent. This property has been strengthened in a variety of ways over the last half-century. Two of the more famous of these strengthenings are the strong variable sharing property and the depth relevance property. In this paper I demonstrate that an appropriate class of relevant logics has a property that might naturally be characterized as the supremum of these (...) two properties. I also show how to use this fact to demonstrate that these logics seem to be constructive in previously unknown ways. (shrink)

Formal symptoms of relevance usually concern the propositional variables shared between the antecedent and the consequent of provable conditionals. Among the most famous results about such symptoms are Belnap’s early results showing that for sublogics of the strong relevant logic R, provable conditionals share a signed variable between antecedent and consequent. For logics weaker than R stronger variable sharing results are available. In 1984, Ross Brady gave one well-known example of such a result. As a corollary to the main result (...) of the paper, we give a very simple proof of a related but strictly stronger result. (shrink)

The Equal Weight View of disagreement says that if an agent sees that an epistemic peer disagrees with her about p, the agent should change her credence in p to half way between her initial credence, and the peer’s credence. But it is hard to believe the Equal Weight View for a surprising reason; not everyone believes it. And that means that if one did believe it, one would be required to lower one’s belief in it in light of this (...) peer disagreement. Brian Weatherson explores the options for how a proponent of the Equal Weight View might respond to this difficulty, and how this challenge fits into broader arguments against the Equal Weight View. (shrink)

There is a natural story about what logic is that sees it as tied up with two operations: a ‘throw things into a bag’ operation and a ‘closure’ operation. In a pair of recent papers, Jc Beall has fleshed out the account of logic this leaves us with in more detail. Using Beall’s exposition as a guide, this paper points out some problems with taking the second operation to be closure in the usual sense. After pointing out these problems, I (...) then turn to fixing them in a restricted case and modulo a few simplifying assumptions. In a followup paper, the simplifications and restrictions will be removed. (shrink)

This paper explores personal identity and persistence through time in the Many Worlds Interpretation (MWI) of quantum mechanics (QM). First, I will motivate the MWI’s relevance in the domain of metaphysics. Second, I will define endurantism. Third, I will explain the foundational physics underlying the MWI which entails branching worlds. Finally, I will argue that the privileged branch view best captures endurantist judgments about personal identity and persistence through time in the many-worlds framework. (Note that this work is in its (...) early draft stages - later versions will be updated and revised). (shrink)

This is an extension of my earlier work, How in the World Are There Many Worlds and it's a lot more interesting! This paper explores personal identity and persistence through time in the many-worlds framework, governed by the Many Worlds Interpretation (MWI) of quantum mechanics (QM). First, I will motivate our consideration of the MWI in this context. Second, I will introduce endurantism, which is one answer to the puzzle concerning persistence through time. Third, I will explain the foundational physics (...) underlying the MWI that lends itself to branching worlds. In turn, I will explain what exactly a world amounts to in this picture. Then, I will present three views on personal identity and persistence through time: the bye-bye Betty view, the every-branch view, and the privileged branch view. I will argue that the privileged branch view is the most attractive of the bunch for determining the best candidate among close continuers. Finally, I will discuss knowledge, attitudes, and moral responsibility within the privileged branch view. (shrink)

In 1988, Kit Fine published a semantic theory for quantified relevant logics. He referred to this theory as stratified semantics. While it has received some attention in the literature, 1–20, 1992; Mares & Goldblatt, Journal of Symbolic Logic 71, 163–187, 2006), stratified semantics has overall received much less attention than it deserves. There are two plausible reasons for this. First, the only two dedicated treatments of stratified semantics available are, 27–59, 1988; Mares, Studia Logica 51, 1–20, 1992), both of which (...) are quite dense and technically challenging. Second, there are a number of prima facie reasons to be worried about stratified semantics. The purpose of this paper is to revitalize research on stratified semantics. I will do so by giving a ‘user friendly’ presentation of the semantics, and by giving reasons to think that the prima facie reasons to be worried about it are too simplistic. (shrink)

Intuitively, Gettier cases are instances of justified true beliefs that are not cases of knowledge. Should we therefore conclude that knowledge is not justified true belief? Only if we have reason to trust intuition here. But intuitions are unreliable in a wide range of cases. And it can be argued that the Gettier intuitions have a greater resemblance to unreliable intuitions than to reliable intuitions. Whats distinctive about the faulty intuitions, I argue, is that respecting them would mean abandoning a (...) simple, systematic and largely successful theory in favour of a complicated, disjunctive and idiosyncratic theory. So maybe respecting the Gettier intuitions was the wrong reaction, we should instead have been explaining why we are all so easily misled by these kinds of cases. (shrink)

Consider the set of inferences that are acceptable to use in all our theory building endeavors. Call this set of inferences the universal theory building toolkit, or just ’the toolkit’ for short. It is clear that the toolkit is tightly connected to logic in a variety of ways. Beall, for example, has argued that logic just is the toolkit. This paper avoids making a stand on that issue and instead investigates reasons for thinking that, logic or not, the toolkit is (...) substructural. It is presented as a dialogue for the simple reason that it summarizes a range of dialogues on this subject that the author has had with various folks over the past few years. The method I use to investigate the toolkit is inspired in both philosophical and technical details by Alasdair Urquhart’s work on semantics for relevance logics from the early 1970s. (shrink)

It has been argued recently that dogmatism in epistemology is incompatible with Bayesianism. That is, it has been argued that dogmatism cannot be modelled using traditional techniques for Bayesian modelling. I argue that our response to this should not be to throw out dogmatism, but to develop better modelling techniques. I sketch a model for formal learning in which an agent can discover a posteriori fundamental epistemic connections. In this model, there is no formal objection to dogmatism.

Intelligent activity requires the use of various intellectual skills. While these skills are connected to knowledge, they should not be identified with knowledge. There are realistic examples where the skills in question come apart from knowledge. That is, there are realistic cases of knowledge without skill, and of skill without knowledge. Whether a person is intelligent depends, in part, on whether they have these skills. Whether a particular action is intelligent depends, in part, on whether it was produced by an (...) exercise of skill. These claims promote a picture of intelligence that is in tension with a strongly intellectualist picture, though they are not in tension with a number of prominent claims recently made by intellectualists. (shrink)

Recently four different papers have suggested that the supervaluational solution to the Problem of the Many is flawed. Stephen Schiffer has argued that the theory cannot account for reports of speech involving vague singular terms. Vann McGee and Brian McLaughlin say that theory cannot, yet, account for vague singular beliefs. Neil McKinnon has argued that we cannot provide a plausible theory of when precisifications are acceptable, which the supervaluational theory needs. And Roy Sorensen argues that supervaluationism is inconsistent with (...) a directly referential theory of names. McGee and McLaughlin see the problem they raise as a cause for further research, but the other authors all take the problems they raise to provide sufficient reasons to jettison supervaluationism. I will argue that none of these problems provide such a reason, though the arguments are valuable critiques. In many cases, we must make some adjustments to the supervaluational theory to meet the posed challenges. The goal of this paper is to make those adjustments, and meet the challenges. (shrink)

I defend normative externalism from the objection that it cannot account for the wrongfulness of moral recklessness. The defence is fairly simple—there is no wrong of moral recklessness. There is an intuitive argument by analogy that there should be a wrong of moral recklessness, and the bulk of the paper consists of a response to this analogy. A central part of my response is that if people were motivated to avoid moral recklessness, they would have to have an unpleasant sort (...) of motivation, what Michael Smith calls “moral fetishism”. (shrink)

This paper argues that the interest-relativity of knowledge cannot be explained by the interest-relativity of belief. The discussion starts with an argument that knowledge plays a key pair of roles in decision theory. It is then argued that knowledge cannot play that role unless knowledge is interest-relative. The theory of the interest-relativity of belief is reviewed and revised. That theory can explain some of the cases that are used to suggest knowledge is interest-relative. But it can’t explain some cases involving (...) ignorance, or mistake, about the odds at which a bet is offered. The paper ends with an argument that these cases require positing interest-relative defeaters, which affect whether an agent knows something without affecting whether she believes it, or is justified in believing it. (shrink)

For some years now, Michael Bergmann has urged a dilemma against internalist theories of epistemic justification. For reasons I explain below, some epistemologists have thought that Michael Huemer’s principle of Phenomenal Conservatism can split the horns of Bergmann’s dilemma. Bergmann has recently argued, however, that PC must inevitably, like all other internalist views, fall prey to his dilemma. In this paper, I explain the nature of Bergmann’s dilemma and his reasons for thinking that PC cannot escape it before arguing that (...) he is mistaken: PC can indeed split its horns. (shrink)

It is still a live question in epistemology and philosophy of science as to what exactly evidence is. In my view, evidence consists in experiences called “seemings.” This view is a version of the phenomenal conception of evidence, the position that evidence consists in nonfactive mental states with propositional content. This conception is opposed by sense-data theorists, disjunctivists, and those who think evidence consists in physical objects or publicly observable states of affairs—call it the courtroom conception of evidence. Thomas Kelly (...) has recently argued that the phenomenal conception cannot play all the roles evidence plays and is thus inadequate. Having first explained the nature of seemings, in this essay I utilize Kelly’s own understanding of the four major roles of evidence and argue that the phenomenal conception can play each one. Experience is a good candidate for evidence. (shrink)

In this paper, I’ll present two objections against Robert Kane’s (2024) libertarian account of free will. First, to accommodate deliberative libertarian views, Kane must reconceptualize how indeterminism operates in deliberation. Second, in light of a discussion concerning the time indeterminism terminates in deliberation, we do not have good reason to prefer Kane’s account over deliberative views. I leave it open as to which view better captures libertarian free will. I only wish to show that deliberative views are no less plausible (...) than Kane’s account. NOTE THAT THIS WORK IS UNPUBLISHED/IN PROGRESS. A better version is coming soon :) . (shrink)

Linnebo and Pettigrew present some objections to category theory as an autonomous foundation. They do a commendable job making clear several distinct senses of ‘autonomous’ as it occurs in the phrase ‘autonomous foundation’. Unfortunately, their paper seems to treat the ‘categorist’ perspective rather unfairly. Several infelicities of this sort were addressed by McLarty. In this note I address yet another apparent infelicity.

In this presentation, I will seek to put into perspective the philosophy and theology of the Seraphic Doctor, St. Bonaventure. I will argue that to understand the thought of St. Bonaventure, one has to understand his Franciscan vocation and the exemplary role of the Seraphic Father, St. Francis. This pattern becomes evident when one looks closer at St. Bonaventure’s (1) exemplary causation, (2) divine illumination theory, (3) and crown of affectivity. Throughout these three topics, it is also my goal to (...) elaborate upon St. Bonaventure’s philosophy by (1) analyzing the respective philosophers who St. Bonaventure responded to (i.e. Aristotle, Plato, St. Augustine, St. Thomas) and (2) contextualizing him among the great Christian thinkers of his time (i.e. St. Thomas and St. Albert). (shrink)

Psychedelic experiences are often compared to “transformative experiences” due to their potential to change how people think and behave. This study empirically examines whether psychedelic experiences constitute transformative experiences. Given psychedelics’ prospective applications as treatments for mental health disorders, this study also explores neuroethical issues raised by the possibility of biomedically directed transformation—namely, consent and moral psychopharmacology. To achieve these aims, we used both inductive and deductive coding techniques to analyze transcripts from interviews with 26 participants in psychedelic retreats. Results (...) indicate that psychedelic experiences can constitute transformative experiences. Twenty participants reported experiences or insights that were seemingly inaccessible or impossible to attain if not for the psychoactive effects of psychedelics. All participants besides one reported some change in identity, values, beliefs, desires, and behavior—changes in behavior being the most common. Participants also reported feeling capable deciding to use psychedelics in part due to information seeking prior to their retreats. Finally, several participants reported an enhanced capacity for enacting changes in their lives. Our results underscore both the importance of subjective embodiment to transformation and the role of transformative agency in shaping outcomes of the psychedelic experience. We examine our results relative to neuroethical issues and advocate for centering the person in psychedelic research and neuroethical inquiry about psychedelics to avoid pitfalls associated with psychedelics’ potential as moral psychopharmacological agents. (shrink)

In this chapter, Logan Paul Gage examines the only real attempt to disprove God’s existence by a New Atheist: Richard Dawkins’s “Ultimate 747 Gambit.” Central to Dawkins’s argument is the claim that God is more complex than what he is invoked to explain. Gage evaluates this claim using the main extant notions of simplicity in the literature. Gage concludes that on no reading does this claim survive scrutiny. Along the way, Dawkins claims that there are no good positive arguments (...) for God’s existence. Gage attempts to show that Dawkins’s argument depends upon distinctively philosophical assumptions that do not appear to withstand scrutiny. (shrink)

Weak enough relevant logics are often closed under depth substitutions. To determine the breadth of logics with this feature, we show there is a largest sublogic of R closed under depth substitutions and that this logic can be recursively axiomatized.

In this paper, we provide a semantics for a range of positive substructural logics, including both logics with and logics without modal connectives. The semantics is novel insofar as it is meant to explicitly capture the computational flavor of these logics, and to do so in a way that builds in both nondeterministic and nonconcurrent computational processes.

Humean supervenience is the conjunction of three theses: Truth supervenes on being, Anti‐haecceitism, and Spatiotemporalism. The first clause is a core part of Lewis's metaphysics. The second clause is related to Lewis's counterpart theory. The third clause says there are no fundamental relations beyond the spatiotemporal, or fundamental properties of extended objects. Supervenience is classified into strong modal Humean supervenience, local modal Humean supervenience and familiar modal Humean supervenience which states that: for any two "worlds like ours", if the spatiotemporal (...) distribution of fundamental qualities is the same at each world, the contingent facts are also the same. The fact that quantum mechanics raises problems for Humean supervenience does not undercut the philosophical significance of Lewis's defense of Humean supervenience. Humean supervenience says that in a world like ours, the fundamental properties are local qualities: perfectly natural intrinsic properties of points, or of point‐sized occupants of points. (shrink)

I consider the problem of how to derive what an agent believes from their credence function and utility function. I argue the best solution of this problem is pragmatic, i.e. it is sensitive to the kinds of choices actually facing the agent. I further argue that this explains why our notion of justified belief appears to be pragmatic, as is argued e.g. by Fantl and McGrath. The notion of epistemic justification is not really a pragmatic notion, but it is being (...) applied to a pragmatically defined concept, i.e. belief. (shrink)

Artificial intelligence (AI) and machine learning (ML) models have undoubtedly become useful tools in science. In general, scientists and ML developers are optimistic – perhaps rightfully so – about the potential that these models have in facilitating scientific progress. The philosophy of AI literature carries a different mood. The attention of philosophers remains on potential epistemological issues that stem from the so-called “black box” features of ML models. For instance, Eamon Duede (2023) argues that opacity in deep learning models (DLMs) (...) is epistemically problematic in the context of justification, though not in the context of discovery. -/- In this paper, I aim to show that a similar epistemological concern is echoed in the epistemology of imagination literature. It is traditionally held that, given its black box features, reliance on the imagination is epistemically problematic in the context of justification, though not in the context of discovery. The constraints-based approach to the imagination answers the epistemological concern by providing an account of how we can rely on the imagination in the context of justification by way of constraints. I argue by analogy that a similar approach can be applied to the opaque DLM case. Ultimately, my goal is to explore just how far this analogy extends, and whether a constraints-based approach to opaque DLMs can answer the epistemological concern surrounding their black box features in the context of justification. -/- (Note that this paper is IN PROGRESS and UNPUBLISHED). (shrink)

In his Principles of Philosophy, Descartes says, Finally, it is so manifest that we possess a free will, capable of giving or withholding its assent, that this truth must be reckoned among the first and most common notions which are born with us.

Accuracy‐first epistemology is an approach to formal epistemology which takes accuracy to be a measure of epistemic utility and attempts to vindicate norms of epistemic rationality by showing how conformity with them is beneficial. If accuracy‐first epistemology can actually vindicate any epistemic norms, it must adopt a plausible account of epistemic value. Any such account must avoid the epistemic version of Derek Parfit's “repugnant conclusion.” I argue that the only plausible way of doing so is to say that accurate credences (...) in certain propositions have no, or almost no, epistemic value. I prove that this is incompatible with standard accuracy‐first arguments for probabilism, and argue that there is no way for accuracy‐first epistemology to show that all credences of all agents should be coherent. (shrink)

Comments on Eugenio Petrovich’s book _A Quantitative Portrait of Analytic Philosophy: Looking Through the Margins_, for the Quantitative Studies of Philosophy workshop at Tilburg, August 21-22 2024.

Ontologies formally represent reality in a way that limits ambiguity and facilitates automated reasoning and data fusion, but is often daunting to the non-technical user. Thus, many researchers have endeavored to hide the formal syntax and semantics of ontologies behind the constructs of Controlled Natural Languages (CNLs), which retain the formal properties of ontologies while simultaneously presenting that information in a comprehensible natural language format. In this paper, we build upon previous work in this field by evaluating prospects of implementing (...) International Technology Alliance Controlled English (ITACE) as a middleware for ontology editing. We also discuss at length a prototype of a natural language conversational interface application designed to facilitate ontology editing via the formulation of CNL constructs. (shrink)

ABSTRACT Quine insisted that the satisfaction of an open modalised formula by an object depends on how that object is described. Kripke's ‘objectual’ interpretation of quantified modal logic, whereby variables are rigid, is commonly thought to avoid these Quinean worries. Yet there remain residual Quinean worries for epistemic modality. Theorists have recently been toying with assignment-shifting treatments of epistemic contexts. On such views an epistemic operator ends up binding all the variables in its scope. One might worry that this yields (...) the undesirable result that any attempt to ‘quantify in’ to an epistemic environment is blocked. If quantifying into the relevant constructions is vacuous, then such views would seem hopelessly misguided and empirically inadequate. But a famous alternative to Kripke's semantics, namely Lewis' counterpart semantics, also faces this worry since it also treats the boxes and diamonds as assignment-shifting devices. As I'll demonstrate, the mere fact that a variable is bound is no obstacle to binding it. This provides a helpful lesson for those modelling de re epistemic contexts with assignment sensitivity, and perhaps leads the way toward the proper treatment of binding in both metaphysical and epistemic contexts: Kripke for metaphysical modality, Lewis for epistemic modality. (shrink)

In previous work I’ve defended an interest-relative theory of belief. This paper continues the defence. It has four aims. -/- 1. To offer a new kind of reason for being unsatis ed with the simple Lockean reduction of belief to credence. 2. To defend the legitimacy of appealing to credences in a theory of belief. 3. To illustrate the importance of theoretical, as well as practical, interests in an interest-relative account of belief. 4. To revise my account to cover propositions (...) that are practically and theoretically irrelevant to the agent. (shrink)

This paper presents a new semantics for the weak relevant logic DW that makes the role of the infamous Routley star more explicable. Central to this rewriting is combining aspects of both the American and Australian plan for understanding negations in relevance logics.

I present a version of Kit Fine's stratified semantics for the logic RWQ and define a natural family of related structures called RW hyperdoctrines. After proving that RWQ is sound with respect to RW hyperdoctrines, we show how to construct, for each stratified model, a hyperdoctrine that verifies precisely the same sentences. Completeness of RWQ for hyperdoctrinal semantics then follows from completeness for stratified semantics, which is proved in an appendix. By examining the base category of RW hyperdoctrines, we find (...) reason to be worried about the ontology of stratified models. (shrink)

An opinionated survey of the state of the literature on interest-relative invariantism.

In this chapter, we argue for a phenomenal conservative perspective on religious epistemology and attempt to answer some common criticisms of this perspective.

Three objections have recently been levelled at the analysis of intrinsicness offered by Rae Langton and David Lewis. While these objections do seem telling against the particular theory Langton and Lewis offer, they do not threaten the broader strategy Langton and Lewis adopt: defining intrinsicness in terms of combinatorial features of properties. I show how to amend their theory to overcome the objections without abandoning the strategy.

In this paper, I will analyze Rawad El Skaf’s (2017 & 2021) account of thought experiments (TEs) in physics. I will argue that El Skaf’s account is strengthened by taking on Amy Kind’s (2016 & 2018) constraints-based approach to the imagination, which highlights the epistemic significance of imaginative processes. First, I will present El Skaf’s step-by-step structure of TEs wherein he discusses their form, content, and epistemic function. Second, I will explain a canonical TE in physics known as the clock-in-the-box. (...) In turn, I will lay out El Skaf’s analysis of the clock-in-the-box TE. Then, I will present Amy Kind’s constraints-based approach to the imagination. I will then offer three critiques of El Skaf’s account and suggest that each critique is resolved by applying a constraints-based approach to his view. Once the hybrid view is laid out, I will discuss incompatible constraints on the imagination, which I call the home and away constraints. I will argue that a thought experimenter (TEer) may overcome this incompatibility by transforming away constraints into home constraints via metaphor. Lastly, I will argue that physics TEs are special since it is an essential feature of theirs that they ask the TEer to consider incompatible constraints on the imagination. (shrink)

A common argument for favouring Evidential Decision Theory (EDT) over Causal Decision Theory (CDT) is that EDT has predictably higher expected returns in Newcomb Problems. But this does not show much. For almost any pair of theories, you can come up with cases where one does, on average, better than the other. Here I describe a case involving dynamic choice where EDT predictably does worse than CDT.

A discussion of several tensions between Thomistic philosophy and modern Darwinian theory as well as several recent Thomistic criticisms of intelligent design.

What question are decision theorists trying to answer, and why is it worth trying to answer it? A lot of philosophers talk as if the aim of decision theory is to describe how we should make decisions, and the reason to do this is to help us make better decisions. I disagree on both fronts. The aim of the decision theory is to describe how a certain kind of idealised decider does in fact decide. And the reason to do this (...) is that this idealisation, like many other idealisations, helps generate explanations of real-world behaviour. We shouldn't do what these ideal deciders do, or try to be more like them, because a lot of what they do only makes sense because of the differences between us and them. Still, sometimes those differences are small enough that they can be ignored in explanations, and that's when decision theory is useful. (shrink)

Abstractionism in the philosophy of mathematics aims at deriving large fragments of mathematics by combining abstraction principles (i.e. the abstract objects $\S e_1, \S e_2$, are identical if, and only if, an equivalence relation $Eq_\S$ holds between the entities $e_1, e_2$) with logic. Still, as highlighted in work on the semantics for relevant logics, there are different ways theories might be combined. In exactly what ways must logic and abstraction be combined in order to get interesting mathematics? In this paper, (...) we investigate the matter by deriving the axioms of second-order Peano Arithmetic from Frege's Basic Law V (the extension of $F$ is identical with the extension of $G$ if, and only if, $F$ and $G$ are extensionally equivalent) in the presence of a relevant higher-order logic. The results are interesting. Not only must we take on logic as true, and not only must we apply our logic to abstraction principles, but also we have to apply our theory of abstraction back to the logic in order to arrive at arithmetic. Thus, what Abstractionism gives us is not simply what we get from abstraction via logic, but also what we get from logic via abstraction. (shrink)

Many writers have held that in his later work, David Lewis adopted a theory of predicate meaning such that the meaning of a predicate is the most natural property that is (mostly) consistent with the way the predicate is used. That orthodox interpretation is shared by both supporters and critics of Lewis's theory of meaning, but it has recently been strongly criticised by Wolfgang Schwarz. In this paper, I accept many of Schwarze's criticisms of the orthodox interpretation, and add some (...) more. But I also argue that the orthodox interpretation has a grain of truth in it, and seeing that helps us appreciate the strength of Lewis's late theory of meaning. (shrink)