Conceptual engineering projects are sometimes criticized for ‘changing the subject’. In this paper, I first discuss three strategies that have been proposed to address the change of subject objection. I notice that these strategies fail in similar ways: they all deploy a ‘loose’ notion of subject matter, while the objector can always reply deploying a ‘strict’ notion. Based on this, I then argue that at least current formulations of the change of subject objection (together with the response strategies just mentioned), (...) create an overall defective dialectic, whereby no progress can be made on either side. After considering how such defective dialectic could be (at least partly) fixed, it is concluded that current formulations of the change of subject objection may be dismissed on dialectical grounds, even though some practical lessons may still be retained from the objection. (shrink)

Conceptual engineers have recently turned to the notion of conceptual functions to do a variety of explanatory work. Functions are supposed to explain what speakers are debating about in metalinguistic negotiations, to capture when two concepts are about the same thing, and to help guide our normative inquiries into which concepts we should use. In this paper, I argue that this recent “functional turn” should be deflated. Contra most interpreters, we should not try to use a substantive notion of conceptual (...) functions to handle various problems for conceptual engineering. The primary accounts of function appealed to by conceptual engineers, namely etiological and system functions, are not suited to handle many of the problems functions are supposed to handle, and it’s dubious whether any other account of function would do better. Instead of trying to use substantive functions to solve theoretical problems, we should deflate those problems themselves by focusing only on what matters to us, as speakers or theorists, in a given inquiry. (shrink)

Steffen Koch raises several objections to my critique of conceptual engineering. Here, I reply to these objections, arguing that Koch fails to adequately defend the “standard rationale” for conceptual engineering, and that the dilemma I have posed for “conceptual re-engineering”, a dilemma that presents this practice as either infeasible or else trivial, survives Koch’s objections unscathed. I conclude that conceptual engineering, both in terms of its conception and rationale, remains problematic.

This paper investigates the connection between two recent trends in philosophy: higher-orderism and conceptual engineering. Higher-orderists use higher-order quantifiers (in particular quantifiers binding variables that occupy the syntactic positions of predicates) to express certain key metaphysical doctrines, such as the claim that there are properties. I argue that, on a natural construal, the higher-orderist approach involves an engineering project concerning, among others, the concept of existence. I distinguish between a modest construal of this project, on which it aims at engineering (...) higher-order analogues of the familiar notion of first-order existence, and an ambitious construal, on which it additionally aims at engineering a broadened notion of existence that subsumes first-order and higher-order existence. After identifying a substantial problem for the ambitious project, I investigate a possible response which is based on adopting a cumulative type theory as the background higher-order logic. While effective against the problem at hand, this strategy turns out to undermine a major reason to embrace higher-orderism in the first place, namely the idea that higher-orderism dissolves a range of otherwise intractable debates in metaphysics. Higher-orderists are therefore best advised to pursue their engineering project on the modest variant and against the background of standard type theory. (shrink)

One important activity in conceptual ethics and conceptual engineering involves proposing to associate a new semantics with an existing word. Many philosophers think that one important way to evaluate such a proposal concerns whether it preserves the “topic” picked out by the existing word, and several have offered competing proposals concerning what is required to preserve topic. Our paper is focused on the conceptual ethics question of how conceptual engineers should use the term ‘topic continuity’. We provide and defend a (...) context-sensitive answer to this question. Our answer is motivated by the idea that there are several distinct considerations that we can reasonably care about (and which many conceptual engineers already do care about) in thinking about “topic continuity”, and, moreover, that how best to weigh them against each other can vary from context to context. On our proposal, ‘topic continuity’ can function as a useful representational device that enables coordination by inquirers with respect to these concerns. We conclude by locating our account in a broader way of thinking about topic continuity across a range of inquiries. (shrink)

Conceptual engineering is the method (or methods) via which we can assess and improve our concepts. Can conceptual engineering be usefully employed within analytic theology? Given that analytic theology and analytic philosophy effectively share the same philosophical toolkit then if conceptual engineering works well in philosophy then it ought to work well in analytic theology too. This will be our working hypothesis. To make good on this hypothesis, we first address two challenges. The first challenge makes conceptual engineering look to (...) be too inclusive; the second challenge makes it look to be too revolutionary (for analytic theology). To address these challenges, we propose a refined characterisation of conceptual engineering. We then turn to consider a number of case studies where analytic theology and conceptual engineering may fruitfully cooperate. These are: theological disagreements, inter-faith dialogue, meaning change, celibacy, AI, the name of God, and conceptual genealogy. (shrink)

This book concerns the foundations of epistemic modality and hyperintensionality and their applications to the philosophy of mathematics. David Elohim examines the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality and hyperintensionality relate to the computational theory of mind; metaphysical modality and hyperintensionality; the types of mathematical modality and hyperintensionality; to the epistemic status of large cardinal axioms, undecidable (...) propositions, and abstraction principles in the philosophy of mathematics; to the modal and hyperintensional profiles of the logic of rational intuition; and to the types of intention, when the latter is interpreted as a hyperintensional mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal and hyperintensional cognitivism and modal and hyperintensional expressivism. Elohim develops a novel, topic-sensitive truthmaker semantics for dynamic epistemic logic, and develops a novel, dynamic two-dimensional semantics grounded in two-dimensional hyperintensional Turing machines. Chapter \textbf{3} provides an abstraction principle for two-dimensional (hyper-)intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal $\mu$-calculus in order to account for the iteration of epistemic states in a single agent, by contrast to availing of modal axiom 4 (i.e. the KK principle). The fixed point operators in the modal $\mu$-calculus are rendered hyperintensional, which yields the first hyperintensional construal of the modal $\mu$-calculus in the literature and the first application of the calculus to the iteration of epistemic states in a single agent instead of the common knowledge of a group of agents. Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's `criterial' identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapters \textbf{2} and \textbf{4} is availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. -/- Chapters \textbf{8-12} provide cases demonstrating how the two-dimensional hyperintensions of hyperintensional, i.e. topic-sensitive epistemic two-dimensional truthmaker, semantics, solve the access problem in the epistemology of mathematics. Chapter \textbf{8} examines the interaction between Elohim's hyperintensional semantics and the axioms of epistemic set theory, large cardinal axioms, the Epistemic Church-Turing Thesis, the modal axioms governing the modal profile of $\Omega$-logic, Orey sentences such as the Generalized Continuum Hypothesis, and absolute decidability. These results yield inter alia the first hyperintensional Epistemic Church-Turing Thesis and hyperintensional epistemic set theories in the literature. Chapter \textbf{9} examines the modal and hyperintensional commitments of abstractionism, in particular necessitism, and epistemic hyperintensionality, epistemic utility theory, and the epistemology of abstraction. Elohim countenances a hyperintensional semantics for novel epistemic abstractionist modalities. Elohim suggests, too, that higher observational type theory can be applied to first-order abstraction principles in order to make first-order abstraction principles recursively enumerable, i.e. Turing machine computable, and that the truth of the first-order abstraction principle for two-dimensional hyperintensions is grounded in its being possibly recursively enumerable and the machine being physically implementable. Chapter \textbf{10} examines the philosophical significance of hyperintensional $\Omega$-logic in set theory and discusses the hyperintensionality of metamathematics. Chapter \textbf{11} provides a modal logic for rational intuition and provides a hyperintensional semantics. Chapter \textbf{12} avails of modal coalgebras to interpret the defining properties of indefinite extensibility, and avails of hyperintensional epistemic two-dimensional semantics in order to account for the interaction between interpretational and objective modalities and the truthmakers thereof. This yields the first hyperintensional category theory in the literature. Elohim invents a new mathematical trick in which first-order structures are treated as categories, and Vopenka's principle can be satisfied because of the elementary embeddings between the categories and generate Vopenka cardinals in the category of Set in category theory. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Elohim provides a counter-example to epistemic closure for logical deduction. Chapter \textbf{14} examines, finally, the modal and hyperintensional semantics for the different types of intention and the relation of the latter to evidential decision theory. (shrink)

Philosophers interested in conceptual engineering take it for granted that the same concept can unproblematically play diverse functions, but this view overlooks the fact that conceptual and functional change often impair concepts and even functions themselves. I demonstrate that while conceptual and functional engineering may improve concepts and functions, they can also produce detrimental effects. Therefore, it is crucial to carefully assess the potential benefits or problems before making any modifications. Frequently, we overlook the fact that, for instance, adding extra (...) functions to our concepts modifies them; this may increase, but also impair, their theoretical and practical efficacy. I analyze and clarify these possibilities through a general classificatory framework encompassing concepts, functions, and conceptual and functional change. The larger aim of this paper is to bring attention to these complex and under-researched relationships and pave the way for further research in this area. (shrink)

A successful lexicographic semantic description characterizes the concepts that occur in establishing the meaning of a listeme by modelling what the competent native-like speaker of the language knows. Because concepts can only be identified to another human through the medium of a natural language, the metalanguage used in the semantic definition of a natural language expression in the object language will always be equivalent to the natural language expression through which that metalanguage is interpreted. The metalanguage of a semantic theory (...) is a demonstrably rational abstract model developed by applying the analyst’s experience and intuitions to inferences drawn from occurrences of actual speech events. Each sense of a listeme is characterized by a description of the salient properties of its typical denotatum. To most effectively implement this project in conceptual engineering is to capture every possible sense of the listeme using metalanguage that is at the same time precise, comprehensive, and succinct. A review of several proposed lexicon/dictionary entries for the listeme cup reveals lacunae that are rectified in a decision procedure whose output characterizes the relevant sense of the input listeme using natural language and the procedural constructs/commands &, XOR, IF, ELSE, ELIF, GOTO, OUTPUT, TENABLE, NEXT ITEM. The resulting lexicographic semantic description satisfies the specified success condition. Establishing the characteristics of metalanguage is crucial to the proper investigation of conceptual engineering. (shrink)

This book concerns the foundations of epistemic modality and hyperintensionality and their applications to the philosophy of mathematics. David Elohim examines the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality and hyperintensionality relate to the computational theory of mind; metaphysical modality and hyperintensionality; the types of mathematical modality and hyperintensionality; to the epistemic status of large cardinal axioms, undecidable (...) propositions, and abstraction principles in the philosophy of mathematics; to the modal and hyperintensional profiles of the logic of rational intuition; and to the types of intention, when the latter is interpreted as a hyperintensional mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal and hyperintensional cognitivism and modal and hyperintensional expressivism. Elohim develops a novel, topic-sensitive truthmaker semantics for dynamic epistemic logic, and develops a novel, dynamic two-dimensional semantics grounded in two-dimensional hyperintensional Turing machines. Chapter \textbf{3} provides an abstraction principle for two-dimensional (hyper-)intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal $\mu$-calculus in order to account for the iteration of epistemic states in a single agent, by contrast to availing of modal axiom 4 (i.e. the KK principle). The fixed point operators in the modal $\mu$-calculus are rendered hyperintensional, which yields the first hyperintensional construal of the modal $\mu$-calculus in the literature and the first application of the calculus to the iteration of epistemic states in a single agent instead of the common knowledge of a group of agents. Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's `criterial' identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapters \textbf{2} and \textbf{4} is availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. -/- Chapters \textbf{8-12} provide cases demonstrating how the two-dimensional hyperintensions of hyperintensional, i.e. topic-sensitive epistemic two-dimensional truthmaker, semantics, solve the access problem in the epistemology of mathematics. Chapter \textbf{8} examines the interaction between Elohim's hyperintensional semantics and the axioms of epistemic set theory, large cardinal axioms, the Epistemic Church-Turing Thesis, the modal axioms governing the modal profile of $\Omega$-logic, Orey sentences such as the Generalized Continuum Hypothesis, and absolute decidability. These results yield inter alia the first hyperintensional Epistemic Church-Turing Thesis and hyperintensional epistemic set theories in the literature. Chapter \textbf{9} examines the modal and hyperintensional commitments of abstractionism, in particular necessitism, and epistemic hyperintensionality, epistemic utility theory, and the epistemology of abstraction. Elohim countenances a hyperintensional semantics for novel epistemic abstractionist modalities. Elohim suggests, too, that higher observational type theory can be applied to first-order abstraction principles in order to make first-order abstraction principles recursively enumerable, i.e. Turing machine computable, and that the truth of the first-order abstraction principle for two-dimensional hyperintensions is grounded in its being possibly recursively enumerable and the machine being physically implementable. Chapter \textbf{10} examines the philosophical significance of hyperintensional $\Omega$-logic in set theory and discusses the hyperintensionality of metamathematics. Chapter \textbf{11} provides a modal logic for rational intuition and provides a hyperintensional semantics. Chapter \textbf{12} avails of modal coalgebras to interpret the defining properties of indefinite extensibility, and avails of hyperintensional epistemic two-dimensional semantics in order to account for the interaction between interpretational and objective modalities and the truthmakers thereof. This yields the first hyperintensional category theory in the literature. Elohim invents a new mathematical trick in which first-order structures are treated as categories, and Vopenka's principle can be satisfied because of the elementary embeddings between the categories and generate Vopenka cardinals in the category of Set in category theory. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Elohim provides a counter-example to epistemic closure for logical deduction. Chapter \textbf{14} examines, finally, the modal and hyperintensional semantics for the different types of intention and the relation of the latter to evidential decision theory. (shrink)