I am a philosopher with wide-ranging research and teaching interests.. My partner is Christina H. Dietz, who is a collegue at Dianoia. I have a daughter, Marlowe, and a son, Sean. I used to play a lot of chess (my ELO peaked around 2330). I am an avid collector of antiquarian books and manuscripts.
After an opening section surveying some possible alternative ways of employing semantic plasticit... more After an opening section surveying some possible alternative ways of employing semantic plasticity to handle the puzzles, this chapter discusses two challenges to the view developed in chapters 11 and 12. One involves the threat of rampant error in counterfactual speech reports. The second involves certain uncomfortable consequences of applying our favoured treatment of words like ‘that’ and ‘table’ to words like ‘I’, ‘you’, ‘person’, ‘thinker’, and ‘conscious’. We show how considerations of semantic plasticity militate in the direction of a kind of “metaphysical misanthropy”, and explore its ethical ramifications.
This is the second of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘i... more This is the second of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘indiscernible modality’, on which qualitative truths are automatically necesssary. This chapter develops our favoured solution to these puzzles, which involves denying the qualitativeness of properties like being a table. We introduce a metaphysical notion of “aboutness” which can be used to probe the sources of non-qualitativeness, and consider some special challenges that arise on the assumption that there could be new objects that aren’t among the objects there actually are.
How should a group with different opinions (but the same values) make decisions? In a Bayesian se... more How should a group with different opinions (but the same values) make decisions? In a Bayesian setting, the natural question is how to aggregate credences: how to use a single credence function to naturally represent a collection of different credence functions. An extension of the standard Dutch-book arguments that apply to individual decision-makers recommends that group credences should be updated by conditionalization. This imposes a constraint on what aggregation rules can be like. Taking conditionalization as a basic constraint, we gather lessons from the established work on credence aggregation, and extend this work with two new impossibility results. We then explore contrasting features of two kinds of rules that satisfy the constraints we articulate: one kind uses fixed prior credences, and the other uses geometric averaging, as opposed to arithmetic averaging. We also prove a new characterisation result for geometric averaging. Finally we consider applications to neighboring philosophical issues, including the epistemology of disagreement
This book didn’t have to consist of exactly the sentences that it in fact contains: any one of it... more This book didn’t have to consist of exactly the sentences that it in fact contains: any one of its sentences could have been very different. But it could not have consisted of an entirely different collection of sentences, such as to make it a gothic novel or a treatise on wine-tasting. Other familiar objects are similarly capable of being moderately different, but not radically different, in various respects. But there are puzzling arguments which threaten these apparently obvious judgments, exploiting the fact that an appropriate sequence of small differences can add up to a radical difference. This book presents the first full-length treatment of these puzzles, using them as an entry point to a broad range of metaphysical questions about possibility, necessity, and identity. It introduces tools of higher-order modal logic which enable a rigorous treatment of the puzzles, and develops a strategy for resolving them based on a plenitudinous ontology of material objects, which induces fine-grained variability in the reference of words like ‘book’
Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Ian... more Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Ian Hacking and Roger White influentially argue that it is not. We approach this question through a systematic framework for self-locating epistemology. As it turns out, leading approaches to self-locating evidence agree that the fact that our own universe contains fine-tuned life indeed confirms the existence of a multiverse (at least in a suitably idealized setting). This convergence is no accident: we present two theorems showing that, in this setting, any updating rule that satisfies a few reasonable conditions will have the same feature. The conclusion that fine-tuned life provides evidence for a multiverse is hard to escape.
This chapter explores Tolerance Puzzles in which the operative modality is that of objective chan... more This chapter explores Tolerance Puzzles in which the operative modality is that of objective chance. We show that a principle of ‘Chance Fixity’, according to which facts about the chances at a given time are not themselves matters of chance at that time, is deeply embedded in ordinary and scientific reasoning about chance and rules out Iteration-denial for the relevant chance operators. We also develop a new ‘Robustness Puzzle’ in which the analogue of Hypertolerance completely untenable. This puzzle turns on strengthenings of Tolerance claims to claims about high (conditional) chance, as opposed to mere positive chance.
This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by... more This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by accepting Hypertolerance, the conclusion that the objects in question could have been arbitrarily different in the respects relevant to the puzzle. This chapter considers what seems to us to be the most promising strategy for arguing against Hypertolerance, based on a physicalist supervenience principle. We show how this principle rules out Hypertolerance in certain “fine-grained” Tolerance Puzzles, and consider to what extent this generalises to other Hypertolerance claims.
This chapter presents the system of classical higher-order modal logic which will be employed thr... more This chapter presents the system of classical higher-order modal logic which will be employed throughout this book. Nothing more than a passing familiarity with classical first-order logic and standard systems of modal logic is presupposed. We offer some general remarks about the kind of commitment involved in endorsing this logic, and motivate some of its more non-standard features. We also discuss how talk about possible worlds can be represented within the system.
This chapter provides a general schema for regimenting a broad family of puzzles of modal variati... more This chapter provides a general schema for regimenting a broad family of puzzles of modal variation. These puzzles begin with a ‘Tolerance’ premise according to which an objects (or a certain kind of object) can differ in any small way along a certain parameter. This is supplemented with a ‘Non-contingency’ premise according to which the Tolerance premise is necessarily true if true at all, an ‘Iteration’ premise according to which anything possibly possible is possible, and a ‘Persistent Closeness’ premise according to which what counts as a ‘small difference’ is modally constant. These premises jointly imply the conclusion, ‘Hypertolerance’, that the object or objects in question can differ arbitrarily along the relevant parameter. We show how this schema is general enough to subsume puzzles involving time or objective chance, and discuss some difficulties that arise in trying to formulate compelling instantiations of the schema involving variation in originating matter.
This chapter presents and discusses a general schema that subsumes a variety of puzzles having to... more This chapter presents and discusses a general schema that subsumes a variety of puzzles having to do with the modal behaviour of material objects, some new and some familiar. These puzzles involve ‘Robustness’ premises according to which certain objects of a given kind are counterfactually robust in certain respects; ‘Non-coincidence’ premises according to which distinct objects of that kind are incapable of coinciding, and ‘Non-distinctness’ premises that rule out the scenarios in which actually distinct objects could have been identical; these jointly entail an absurd conclusion.
This chapter takes up the question of how to motivate the crucial ‘Non-Contingency’ premise in th... more This chapter takes up the question of how to motivate the crucial ‘Non-Contingency’ premise in the Tolerance Puzzles introduced in Chapter 2, a question that has received surprisingly little attention in the literature on these puzzles. We articulate and set aside some dubious motivations for the premise, including motivations which assimilate Tolerance Puzzles to the well-known Sorites Paradox. In place of these, we develop a ‘Security Argument’ for Non-contingency, based on the thought that it is not just a matter of chance or luck that we avoid error in believing the Tolerance premise.
This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by ... more This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by denying Iteration, the claim that whatever is possibly possible is possible. In this chapter we grant for the sake of argument that Iteration fails for metaphysical necessity, and consider whether there are other Tolerance Puzzles which remain problematic even on that assumption. Our main focus is on puzzles involving ancestral metaphysical possibility—the status of being either possible, or possibly possible, or possibly possibly possible, or…—for which Iteration is guaranteed by our basic modal logic. We argue that plausible higher-order identities suggest that ancestral metaphysical possibility is not a trivial status even for those who deny Iteration for metaphysical possibility.
This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by ... more This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by accepting Hypertolerance, the conclusion that the objects in question could have been arbitrarily different in the respects relevant to the puzzle. This chapter discusses two influential objections to certain Hypertolerance claims, one based on the doctrine of ‘Anti-haecceitism’ (according to which an object’s qualitative profile suffices for its identity), and another based on the doctrine of ‘Overlap Essentialism’ (according to which a table originally made of certain matter could not have been originally made of entirely non-overlapping matter). We consider some arguments for Overlap Essentialism from certain ‘sufficiency of origin’ principles, and discuss some difficult cases which put pressure on Overlap Essentialism.
This chapter further develops the framework introduced in the previous chapter. We suggest that t... more This chapter further develops the framework introduced in the previous chapter. We suggest that the best approach to many Tolerance Puzzles involves some contextual flexibility, allowing not only for contexts in which Non-contingency is false but also for contexts in which Hypertolerance is true. We discuss how plasticity and plenitude can also be used to solve the Coincidence Puzzles introduced in chapter 4, and conclude by considering a range of open questions and case studies.
This chapter develops a strategy for resolving Tolerance Puzzles based on two central ideas. The ... more This chapter develops a strategy for resolving Tolerance Puzzles based on two central ideas. The first idea is a principle of ‘plenitude’, according to which any given material objects coincides with innumerably many others differing from it in a wide variety of modal respects. The second idea is that because of this plenitude of candidate referents, the singular terms (like ‘this table’) and common nouns (like ‘table’) that feature in Tolerance Puzzles are subject to a high degree of semantic plasticity: small changes in the world, e.g. in the selection of parts to be made into tables, suffice to make a difference to what we refer to with these words. Such plasticity undermines the Security Argument for Non-contingency developed in chapter 2, by suggesting that even though Tolerance could easily have been false, Tolerance speeches robustly express truths.
This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by... more This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by denying Iteration, the claim that whatever is possibly possible is possible. This chapter argues for Iteration for metaphysical possibility, based on the premise that metaphysical possibility is the broadest form of possibility. Some reject this on the grounds that, for example, it is logically possible (although metaphysically impossible) that Hesperus is distinct from Phosphorus. We show that those who accept this premise should reject the form of existential generalization required to derive the conclusion that there is a form of possibility that attaches to the proposition that Hesperus is distinct from Phosphorus. We show how under certain attractive assumptions about the grain of higher-order reality one can show that there is a broadest form of possibility, and indeed define it in purely logical terms.
This is the first of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘in... more This is the first of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘indiscernible modality’, on which qualitative truths are automatically necesssary. The interest in these puzzles lies in the fact that there is a distinctive argument for Non-contingency based on the premise that properties like being a table are qualitative. This chapter explores the options for resolving the puzzles compatible with accepting that premise, and hence Non-contingency for indiscernible modality.
Many philosophers have thought that Tolerance Puzzles can be easily dissolved by adopting some fo... more Many philosophers have thought that Tolerance Puzzles can be easily dissolved by adopting some form of counterpart theory, which is roughly the view that being possibly a certain way is having a counterpart that is that way. This chapter shows how standard versions of counterpart theory involve radical departures from standard modal logic (going far beyond Iteration-denial) which we claim are unacceptable, and argues that once counterpart theory is developed in such a way as to avoid such logical revisionism, it has no special capacity to resolve the puzzles.
After an opening section surveying some possible alternative ways of employing semantic plasticit... more After an opening section surveying some possible alternative ways of employing semantic plasticity to handle the puzzles, this chapter discusses two challenges to the view developed in chapters 11 and 12. One involves the threat of rampant error in counterfactual speech reports. The second involves certain uncomfortable consequences of applying our favoured treatment of words like ‘that’ and ‘table’ to words like ‘I’, ‘you’, ‘person’, ‘thinker’, and ‘conscious’. We show how considerations of semantic plasticity militate in the direction of a kind of “metaphysical misanthropy”, and explore its ethical ramifications.
This is the second of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘i... more This is the second of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘indiscernible modality’, on which qualitative truths are automatically necesssary. This chapter develops our favoured solution to these puzzles, which involves denying the qualitativeness of properties like being a table. We introduce a metaphysical notion of “aboutness” which can be used to probe the sources of non-qualitativeness, and consider some special challenges that arise on the assumption that there could be new objects that aren’t among the objects there actually are.
How should a group with different opinions (but the same values) make decisions? In a Bayesian se... more How should a group with different opinions (but the same values) make decisions? In a Bayesian setting, the natural question is how to aggregate credences: how to use a single credence function to naturally represent a collection of different credence functions. An extension of the standard Dutch-book arguments that apply to individual decision-makers recommends that group credences should be updated by conditionalization. This imposes a constraint on what aggregation rules can be like. Taking conditionalization as a basic constraint, we gather lessons from the established work on credence aggregation, and extend this work with two new impossibility results. We then explore contrasting features of two kinds of rules that satisfy the constraints we articulate: one kind uses fixed prior credences, and the other uses geometric averaging, as opposed to arithmetic averaging. We also prove a new characterisation result for geometric averaging. Finally we consider applications to neighboring philosophical issues, including the epistemology of disagreement
This book didn’t have to consist of exactly the sentences that it in fact contains: any one of it... more This book didn’t have to consist of exactly the sentences that it in fact contains: any one of its sentences could have been very different. But it could not have consisted of an entirely different collection of sentences, such as to make it a gothic novel or a treatise on wine-tasting. Other familiar objects are similarly capable of being moderately different, but not radically different, in various respects. But there are puzzling arguments which threaten these apparently obvious judgments, exploiting the fact that an appropriate sequence of small differences can add up to a radical difference. This book presents the first full-length treatment of these puzzles, using them as an entry point to a broad range of metaphysical questions about possibility, necessity, and identity. It introduces tools of higher-order modal logic which enable a rigorous treatment of the puzzles, and develops a strategy for resolving them based on a plenitudinous ontology of material objects, which induces fine-grained variability in the reference of words like ‘book’
Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Ian... more Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Ian Hacking and Roger White influentially argue that it is not. We approach this question through a systematic framework for self-locating epistemology. As it turns out, leading approaches to self-locating evidence agree that the fact that our own universe contains fine-tuned life indeed confirms the existence of a multiverse (at least in a suitably idealized setting). This convergence is no accident: we present two theorems showing that, in this setting, any updating rule that satisfies a few reasonable conditions will have the same feature. The conclusion that fine-tuned life provides evidence for a multiverse is hard to escape.
This chapter explores Tolerance Puzzles in which the operative modality is that of objective chan... more This chapter explores Tolerance Puzzles in which the operative modality is that of objective chance. We show that a principle of ‘Chance Fixity’, according to which facts about the chances at a given time are not themselves matters of chance at that time, is deeply embedded in ordinary and scientific reasoning about chance and rules out Iteration-denial for the relevant chance operators. We also develop a new ‘Robustness Puzzle’ in which the analogue of Hypertolerance completely untenable. This puzzle turns on strengthenings of Tolerance claims to claims about high (conditional) chance, as opposed to mere positive chance.
This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by... more This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by accepting Hypertolerance, the conclusion that the objects in question could have been arbitrarily different in the respects relevant to the puzzle. This chapter considers what seems to us to be the most promising strategy for arguing against Hypertolerance, based on a physicalist supervenience principle. We show how this principle rules out Hypertolerance in certain “fine-grained” Tolerance Puzzles, and consider to what extent this generalises to other Hypertolerance claims.
This chapter presents the system of classical higher-order modal logic which will be employed thr... more This chapter presents the system of classical higher-order modal logic which will be employed throughout this book. Nothing more than a passing familiarity with classical first-order logic and standard systems of modal logic is presupposed. We offer some general remarks about the kind of commitment involved in endorsing this logic, and motivate some of its more non-standard features. We also discuss how talk about possible worlds can be represented within the system.
This chapter provides a general schema for regimenting a broad family of puzzles of modal variati... more This chapter provides a general schema for regimenting a broad family of puzzles of modal variation. These puzzles begin with a ‘Tolerance’ premise according to which an objects (or a certain kind of object) can differ in any small way along a certain parameter. This is supplemented with a ‘Non-contingency’ premise according to which the Tolerance premise is necessarily true if true at all, an ‘Iteration’ premise according to which anything possibly possible is possible, and a ‘Persistent Closeness’ premise according to which what counts as a ‘small difference’ is modally constant. These premises jointly imply the conclusion, ‘Hypertolerance’, that the object or objects in question can differ arbitrarily along the relevant parameter. We show how this schema is general enough to subsume puzzles involving time or objective chance, and discuss some difficulties that arise in trying to formulate compelling instantiations of the schema involving variation in originating matter.
This chapter presents and discusses a general schema that subsumes a variety of puzzles having to... more This chapter presents and discusses a general schema that subsumes a variety of puzzles having to do with the modal behaviour of material objects, some new and some familiar. These puzzles involve ‘Robustness’ premises according to which certain objects of a given kind are counterfactually robust in certain respects; ‘Non-coincidence’ premises according to which distinct objects of that kind are incapable of coinciding, and ‘Non-distinctness’ premises that rule out the scenarios in which actually distinct objects could have been identical; these jointly entail an absurd conclusion.
This chapter takes up the question of how to motivate the crucial ‘Non-Contingency’ premise in th... more This chapter takes up the question of how to motivate the crucial ‘Non-Contingency’ premise in the Tolerance Puzzles introduced in Chapter 2, a question that has received surprisingly little attention in the literature on these puzzles. We articulate and set aside some dubious motivations for the premise, including motivations which assimilate Tolerance Puzzles to the well-known Sorites Paradox. In place of these, we develop a ‘Security Argument’ for Non-contingency, based on the thought that it is not just a matter of chance or luck that we avoid error in believing the Tolerance premise.
This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by ... more This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by denying Iteration, the claim that whatever is possibly possible is possible. In this chapter we grant for the sake of argument that Iteration fails for metaphysical necessity, and consider whether there are other Tolerance Puzzles which remain problematic even on that assumption. Our main focus is on puzzles involving ancestral metaphysical possibility—the status of being either possible, or possibly possible, or possibly possibly possible, or…—for which Iteration is guaranteed by our basic modal logic. We argue that plausible higher-order identities suggest that ancestral metaphysical possibility is not a trivial status even for those who deny Iteration for metaphysical possibility.
This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by ... more This is the first of two chapters exploring the option of resolving various Tolerance Puzzles by accepting Hypertolerance, the conclusion that the objects in question could have been arbitrarily different in the respects relevant to the puzzle. This chapter discusses two influential objections to certain Hypertolerance claims, one based on the doctrine of ‘Anti-haecceitism’ (according to which an object’s qualitative profile suffices for its identity), and another based on the doctrine of ‘Overlap Essentialism’ (according to which a table originally made of certain matter could not have been originally made of entirely non-overlapping matter). We consider some arguments for Overlap Essentialism from certain ‘sufficiency of origin’ principles, and discuss some difficult cases which put pressure on Overlap Essentialism.
This chapter further develops the framework introduced in the previous chapter. We suggest that t... more This chapter further develops the framework introduced in the previous chapter. We suggest that the best approach to many Tolerance Puzzles involves some contextual flexibility, allowing not only for contexts in which Non-contingency is false but also for contexts in which Hypertolerance is true. We discuss how plasticity and plenitude can also be used to solve the Coincidence Puzzles introduced in chapter 4, and conclude by considering a range of open questions and case studies.
This chapter develops a strategy for resolving Tolerance Puzzles based on two central ideas. The ... more This chapter develops a strategy for resolving Tolerance Puzzles based on two central ideas. The first idea is a principle of ‘plenitude’, according to which any given material objects coincides with innumerably many others differing from it in a wide variety of modal respects. The second idea is that because of this plenitude of candidate referents, the singular terms (like ‘this table’) and common nouns (like ‘table’) that feature in Tolerance Puzzles are subject to a high degree of semantic plasticity: small changes in the world, e.g. in the selection of parts to be made into tables, suffice to make a difference to what we refer to with these words. Such plasticity undermines the Security Argument for Non-contingency developed in chapter 2, by suggesting that even though Tolerance could easily have been false, Tolerance speeches robustly express truths.
This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by... more This is the second of two chapters exploring the option of resolving various Tolerance Puzzles by denying Iteration, the claim that whatever is possibly possible is possible. This chapter argues for Iteration for metaphysical possibility, based on the premise that metaphysical possibility is the broadest form of possibility. Some reject this on the grounds that, for example, it is logically possible (although metaphysically impossible) that Hesperus is distinct from Phosphorus. We show that those who accept this premise should reject the form of existential generalization required to derive the conclusion that there is a form of possibility that attaches to the proposition that Hesperus is distinct from Phosphorus. We show how under certain attractive assumptions about the grain of higher-order reality one can show that there is a broadest form of possibility, and indeed define it in purely logical terms.
This is the first of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘in... more This is the first of two chapters devoted to a special subclass of Tolerance Puzzles based on ‘indiscernible modality’, on which qualitative truths are automatically necesssary. The interest in these puzzles lies in the fact that there is a distinctive argument for Non-contingency based on the premise that properties like being a table are qualitative. This chapter explores the options for resolving the puzzles compatible with accepting that premise, and hence Non-contingency for indiscernible modality.
Many philosophers have thought that Tolerance Puzzles can be easily dissolved by adopting some fo... more Many philosophers have thought that Tolerance Puzzles can be easily dissolved by adopting some form of counterpart theory, which is roughly the view that being possibly a certain way is having a counterpart that is that way. This chapter shows how standard versions of counterpart theory involve radical departures from standard modal logic (going far beyond Iteration-denial) which we claim are unacceptable, and argues that once counterpart theory is developed in such a way as to avoid such logical revisionism, it has no special capacity to resolve the puzzles.
(A lightly edited transcript of a pre-read talk I gave at Oxford some years ago for a series of t... more (A lightly edited transcript of a pre-read talk I gave at Oxford some years ago for a series of talks organized by Ofra Magidor. I plan to publish some version it some time in a planned collection of epistemological essays.)
Many philosophers think that given the choice between saving the life of an innocent person and a... more Many philosophers think that given the choice between saving the life of an innocent person and averting many minor ailments or inconveniences, it would be better to save the life. These intuitions concern cases where stakes are certain––X many headaches vs. a life. It is less clear how to accommodate cases with uncertain stakes––X many headaches vs. some nonzero probability of risk to a life. This paper explores one of the more promising strategies for developing an absolutist approach for decisions under uncertainty.
We begin with a puzzle that is adequately solved by appeal to certain facts
about our assessment ... more We begin with a puzzle that is adequately solved by appeal to certain facts about our assessment procedures for conditionals combined with certain facts about the structure of knowledge. That solution is unavailable to proponents of KK. This, we argue, is a signi cant cost for KK. We go on to defuse a battery of arguments due to Kevin Dorst that try to motivate KK on the basis of the infelicity of a di erent class of conditionals. Along the way we expose the defects of some prima facie promising ideas about how to assess conditionals for their assertability.
A version of this will appear in Oxford Studies in Metaphysics.
Erratum: On page 26 line 16, in ... more A version of this will appear in Oxford Studies in Metaphysics. Erratum: On page 26 line 16, in the displayed indented formula, the existential quantifer should have scope over the diamond.
Normality is commonplace. We routinely distinguish normal weather from hurricanes and droughts; n... more Normality is commonplace. We routinely distinguish normal weather from hurricanes and droughts; normal prices from bargains and rip-offs; and normal behavior from eccentricity and oddity. Not only do we form judgments about normality with ease, but facts about what is normal serve as a reliable guide to navigating the world. Knowing the normal presentation of a disease can help a doctor to successfully diagnose a patient. Knowing the normal level of rush hour traffic can help a commuter to arrive on time. And knowing the normal migration patterns of birds can help ornithologists to identify species. Our subject in this paper is the modality of normality. Items of a variety of types can be evaluated for normality. For example, we can readily compare the normality of individuals, kinds and properties. Gerald Ford was more normal, for a president, than Richard Nixon. Weasels are more normal, for mammals, than wombats. And being tall is more normal, for basketball players, than being short. The modality of normality, in contrast, has to do with properties of states of affairs.There may be interesting connections between the properties of individuals, kinds and properties and the modality of normality. However, in what follows, our attention will be focused exclusively on facts about the latter.
Recent research has identified a tension between the Safety principle that knowledge is belief wi... more Recent research has identified a tension between the Safety principle that knowledge is belief without risk of error, and the Closure principle that knowledge is preserved by competent deduction.Timothy Williamson reconciles Safety and Closure by proposing that when an agent deduces a conclusion from some premises, the agent’s method for believing the conclusion includes their method for believing each premise. We argue that this theory is untenable because it impliesMethod Luminosity, the thesis that whenever an agent believes p using a method, the agent is in a position to know they believed p using that method. Several possible solutions are explored and rejected
In preface cases, people believe that some of their beliefs are false. Many have considered what ... more In preface cases, people believe that some of their beliefs are false. Many have considered what such people are justified in believing. We turn our attention to what they can know. We introduce a novel 'archipelago puzzle', showing that if deduction extends knowledge, then ordinary knowledge of error can lead in surprising ways to the absurdly pessimistic knowledge that most of one's beliefs are false.
In 1978, Eric Kraemer observed that 'Brown intentionally threw a six' and 'Brown intentionally wo... more In 1978, Eric Kraemer observed that 'Brown intentionally threw a six' and 'Brown intentionally won the game' can differ in truth-value, even when it is known that Brown won the game just in case he threw a six. More generally, there are cases where S intentionally V 1 and S intentionally V 2 differ in truth-value even though V 1 and V 2 are known to be co-extensive. We call this Kraemer's puzzle in the theory of intentional action. We bring out some of the puzzle's central features, and gesture towards a solution.
(Forthcoming in Externalism About Knowledge, edited by Luis Oliveira) , 2021
The so-called safety conception of knowledge enjoys considerable popularity, but there are import... more The so-called safety conception of knowledge enjoys considerable popularity, but there are important choice points when it comes to its articulation and deployment. In this essay we explore a number of them and also make vivid some important challenges to various versions of the safety approach. In section one we present some key facets of Williamson’s presentation of safety. In section two, we present five important choice points for the safety theorist. In section three, we discuss an important issue concerning methodological orientation that turns on the difference between analysis and model-building.
Inheritance is the principle that deontic 'ought' is closed under entailment. This paper is about... more Inheritance is the principle that deontic 'ought' is closed under entailment. This paper is about a tension that arises in connection with Inheritance. More specifically, it is about two observations that pull in opposite directions. One of them raises questions about the validity of Inheritance, while the other appears to provide strong support for it. We argue that existing approaches to deontic modals fail to provide us with an adequate resolution of this tension. In response, we develop a positive analysis, and show that this proposal provides a satisfying account of our intuitions.
Here is a second sample chapter from the The Bounds of Possibility, co-authored with Cian Dorr an... more Here is a second sample chapter from the The Bounds of Possibility, co-authored with Cian Dorr and Juhani Yli-Vakkuri forthcoming with OUP
Introductory Chapter to The Bounds of Possibility: Puzzles of Modal Variation
Cian Dorr, John H... more Introductory Chapter to The Bounds of Possibility: Puzzles of Modal Variation
Cian Dorr, John Hawthorne and Juhani Yli-Vakkuri, forthcoming OUP.
The final version will appear in the Journal of Ethics and Social Philosophy
Epistemicism is one of the main approaches to the phenomenon of vagueness. But how does it far in... more Epistemicism is one of the main approaches to the phenomenon of vagueness. But how does it far in its treatment of moral vagueness? This paper has two goals. First, I shall explain why various recent arguments against an epistemicist approach to moral vagueness are unsuccessful. Second, I shall explain how, in my view, reflection on the Sorites can inform normative ethics in powerful and interesting ways. In this connection, I shall be putting the epistemicist treatment to work.
A slightly later version is forthcoming in The Journal of Philosophy
The analysis of desire ascriptions has been a central topic of research for philosophers of langu... more The analysis of desire ascriptions has been a central topic of research for philosophers of language and mind. This work has mostly focused on providing a theory of want reports, i.e. sentences of the form S wants p. In this paper, we turn attention from want reports to a closely related, but relatively understudied construction, namely hope reports, i.e. sentences of the form S hopes p. We present two contrasts involving hope reports, and show that existing approaches to desire fail to explain these contrasts. We then develop a novel account that combines some of the central insights in the literature. We argue that our theory provides us with an elegant account of our contrasts, and yields a promising analysis of hoping.
Forthcoming, The Philosophical Review (this is the penultimate version)
Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Hac... more Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Hacking (1987) and White (2000) influentially argue that it is not. Subsequent debate on this question has centered on competing analogies; but it is not clear which of these analogies are apt. We instead approach the question through a systematic framework for self-locating epistemology. As it turns out, all leading approaches to self-locating evidence agree that the fact that our own universe contains fine-tuned life indeed confirms the existence of a multiverse (at least in a suitably idealized setting). This convergence is no accident: we present two theorems that in this setting, any updating rule that satisfies a few reasonable conditions will have the same feature. The conclusion that fine-tuned life provides evidence for a multiverse is hard to escape.
A later version is forthcoming in the Australasian Journal of Philosophy
Many defend the thesis that knowledge requires safety from error, so that when someone knows p, t... more Many defend the thesis that knowledge requires safety from error, so that when someone knows p, they couldn't easily have been wrong about p. This paper investigates the principle of Counterfactual Closure (CC), which connects knowledge and counterfactuals: if it easily could have happened that p, and if p were the case, then q would be the case, it follows that it easily could have happened that q. We use CC to probe the viability of various models of knowledge. We first show that an unrestricted version of CC is false. This falsifies a model where the easy possibilities are counterfactually similar to actuality. We next show that normality models of knowledge predict that CC fails. Here, the easy possibilities are the sufficiently normal worlds. We then offer a true restriction of CC. This principle says that p is an easy possibility when p counterfactually depends on a coin flip. We show that restricted CC is invalidated by extant normality theories. Finally, we enrich normality theories with the principle of Counterfactual Contamination, which says that any world is fairly abnormal if at that world very abnormal events counterfactually depend on a coin flip.
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Papers by John Hawthorne
about our assessment procedures for conditionals combined with certain facts about the structure of knowledge. That solution is unavailable to proponents of KK. This, we argue, is a signi cant cost for KK. We go on to defuse a battery of arguments due to Kevin Dorst that try to motivate KK on the basis of the infelicity of a di erent class of conditionals. Along the way we expose the defects of some prima facie promising ideas about how to assess conditionals for their assertability.
Erratum: On page 26 line 16, in the displayed indented formula, the existential quantifer should have scope over the diamond.
normality of individuals, kinds and properties. Gerald Ford was more normal, for a president, than Richard Nixon. Weasels are more normal, for mammals, than wombats. And being tall is more normal, for basketball players, than being short. The modality of normality, in contrast, has to do with properties of states of affairs.There may be interesting connections between the properties of individuals, kinds and properties and the modality of normality. However, in what follows, our attention will be focused exclusively on facts about the latter.
Cian Dorr, John Hawthorne and Juhani Yli-Vakkuri, forthcoming OUP.