Jessica Leech

According to an increasingly popular view, the source of logical necessity is to be found in the essences of logical entities. One might be tempted to extend the view further in using it to tackle fundamental questions surrounding logical consequence. This chapter enquires: how does a view according to which the facts about logical consequence are determined by the essences of logical entities look in detail? Are there any more or less obvious problems arising for such a view? The chapter uncovers a _prima facie_ result in favour of logical pluralism. However, it then goes on to raise some concerns for this result. It argues that, considered generally, it is difficult to see how essence could do all of the requisite work alone. The chapter also shows how considering things from the perspective of disputes between particular rival logics makes an interesting and important difference to the picture of things presented by the essentialist account.

I offer a brief introduction to my book, Thinking of Necessity, and respond to discussions by Sam Kimpton-Nye, Sònia Roca Royes, and Naomi Thompson. I engage with Thompson on questions concerning the distinction between subjective and objective thought, and the role this distinction plays in my account of the role of modal concepts. I engage with Kimpton-Nye on questions concerning the relation between metaphysical and natural necessity, and the duality of possibility and necessity, and constraints on real modality. I engage with Roca Royes on questions concerning metaphysical necessity as the strictest real necessity, de re necessity, and implications for my account of metaphysical necessity.

For most readers of the Proceedings of the Aristotelian Society, Peter Momtchiloff needs little introduction. From 1993 to 2023 he was Commissioning Editor for Philosophy at Oxford University Press (OUP). It was big news in the philosophy community when we heard that Peter was leaving his post in December 2023. In July 2024 we invited Peter along to talk to us at the Aristotelian Society to find out a bit about what he's seen and what he's learned. The discussion between Peter, Jessica Leech and Ellie Robson was shared as a podcast. What follows is an edited version of that discussion for our readers.

One of Kant’s categories—a priori concepts the possession and applicability of which are necessary conditions of possible experience—is a concept of necessity. But it is unclear why the concept of necessity, as Kant defines it, should be a category thus understood. My aim is to offer a reading of Kant that fills this lacuna: the category of necessity is required to make necessity as it features in the world of experience understandable: a concept that the understanding can grasp and employ in cognition of objects. Kant’s view has potential wider significance for accounts of the function of necessity judgments.

The aim of this paper is to make some headway in understanding the notion of zero-grounding. The account of grounding in terms of generalized identity, proposed by Correia and Skiles (2019), is employed to clarify issues of ground and zero-ground. I discuss some options for accommodating zero-grounding. According to one option, we slide dangerously close to violating the irreflexivity of ground. According to another option, zero-grounding leads to a worrying kind of overdetermination. A third option offers a way out, but a challenge remains of how best to make sense of it. I further contend that these arguments broaden to concern any notion of grounding according to which groundees are “nothing over and above” their grounds. Ultimately, the aim of this paper is exploratory. It lays out some of the different options and challenges that face the grounding theorist who wants to make sense of zero-grounding.

Questions of persistence and change are central to metaphysics. There is almost always a role for sortal or essential properties to play in theories of persistence. However, one might reasonably be suspicious of many of the claims about sortal properties and essential properties on which so many accounts of persistence conditions rest. The aim of this paper is to think through what persistence looks like if we don't help ourselves to these assumptions. In so doing, we shall uncover a deep and difficult problem when it comes to identity facts and their relation to qualitative facts. Towards the end of the paper, I sketch a potential line of response that builds upon our seeming awareness of a genuinely persisting self.

Kant distinguishes cognition and thought. Mere thoughts do not conform to the conditions that Kant places on cognition and hence do not represent objects of experience. They are, nevertheless, intelligible, and play a vital role in our mental and moral lives. I offer the beginnings of an account of mere thought using Kant's resources. I consider four key cases of intelligible representations that lack objective validity: unschematized categories; transcendental ideas; philosophical concepts; thoughts that violate principles of the understanding.

The aim of this chapter is to explore to some extent the relationship between identity and necessity in logic and metaphysics. First, I provide a historically-based summary of proofs of the necessity of identity, highlighting the importance of the role that self-identity plays. Second, I introduce two examples of metaphysical topics where the necessity of identity has played a pivotal role: the necessary a posteriori, and the coincidence of material objects. I argue that important aspects of these debates rest on how we represent identity. Third, I consider some recent work on generalized identity. This opens up new prospects for explaining why identity is necessary.

This book sets out a Kant-inspired theory of modality, driven by a methodology which takes seriously questions about the function of modal judgment as a guide to a metaphysics of modality. It argues that we need logical modal concepts as a condition on our ability to think, and metaphysical modal concepts as a condition on our ability to think objectively. Concordant with this, it argues that logical necessity has its source in the laws of thought and that metaphysical necessity is relative to conditions on objective thought. This this account of metaphysical necessity, which is termed “Modal Transcendentalism”, is then further developed, covering questions concerning necessary and contingent existence, de re necessity, essentialism, and modal epistemology.

Since the publication of Kit Fine's “Essence and Modality”, there has been lively debate over how best to think of essence in relation to necessity. The present aim is to draw attention to a definition of essence in terms of modality that has not been given sufficient attention. This neglect is perhaps unsurprising, since it is not a proposal made in response to Fine's 1994 paper and ensuing discussion, but harks back to Ruth Barcan Marcus's earlier work in the 1960s and 1970s on essentialist claims. At the core of Barcan Marcus's account is Minimal Essentialism, of which there are several extensions, in particular, for cases of referential predicates (such as “x is identical to Socrates”), Individuating Essentialism, and Aristotelian Essentialism. I argue that Minimal Essentialism fares favourably against a host of familiar examples. I close with some historical observations, that the distinction between essence and necessity was already commonplace in the early days of quantified modal logic and its philosophy.

Recently, a debate has developed between those who claim that essence can be explained in terms of de re modality (modalists), and those who claim that de re modality can be explained in terms of essence (essentialists). The aim of this paper is to suggest that we should reassess. It is assumed that either necessity is to be accounted for in terms of essence, or that essence is to be accounted for in terms of necessity. I will argue that we should assume neither. I discuss what role these key notions – essence and necessity – can reasonably be thought to contribute to our understanding of the world, and argue that, given these roles, there is no good reason to think that we should give an account of one in terms of the other. I conclude: if we can adequately explain de re modality and essence at all, we should aim to do so separately.

According to an increasingly popular view, the source of logical necessity is to be found in the essences of logical entities. One might be tempted to extend the view further in using it to tackle fundamental questions surrounding logical consequence. This chapter enquires: how does a view according to which the facts about logical consequence are determined by the essences of logical entities look in detail? Are there any more or less obvious problems arising for such a view? The chapter uncovers a prima facie result in favour of logical pluralism. However, it then goes on to raise some concerns for this result. It argues that, considered generally, it is difficult to see how essence could do all of the requisite work alone. The chapter also shows how considering things from the perspective of disputes between particular rival logics makes an interesting and important difference to the picture of things presented by the essentialist account.

This book is a collection of essays written by Bob Hale (three co-authored), with a critical introduction from Kit Fine. They comprise Hale’s final years of work, adding to and extending beyond his landmark monograph Necessary Beings: An Essay on Ontology, Modality, and the Relations Between Them (OUP, 2013, 2nd edition 2015). The essays develop and consolidate several key themes in Hale’s work, most notably the notion of definition, especially as it extends beyond definition of a word to definition of a thing more generally, and its relations to essence and existence; how the recently influential notion of truthmaking relates to and illuminates some of these issues; and ontological questions connected with Hale’s metaphysical commitments on the one hand, and his commitments in the foundations of mathematics on the other. Several of the essays engage with and respond to work by Kit Fine, and contributions to Being Necessary: Themes of Ontology and Modality from the Work of Bob Hale (OUP 2018). As such, these essays also demonstrate a rich and fruitful philosophical dialogue between Hale and his critics and friends.

Edited by Ivette Fred-Rivera and Jessica Leech. What is the relationship between ontology and modality: between what there is, and what there could be, must be, or might have been? Throughout a distinguished career, Bob Hale’s work has addressed this question on a number of fronts, through the development of a Fregean approach to ontology, an essentialist theory of modality, and in his work on neo-logicism in the philosophy of mathematics. This collection of new essays engages with these themes in Hale’s work in order to make further progress in our understanding of ontology, modality, and the relations between them. Some essays directly address questions in modal metaphysics, drawing on ontological concerns. Others raise questions in modal epistemology and its links to matters of ontology, such as the challenge to give an epistemology of essence. There are also several essays engaging with questions of what might be called ‘modal ontology’: the study of whether and what things exist necessarily or contingently. Such issues can be raised and addressed directly, but they also have an important bearing on the kinds of semantic commitments engendered in logic and mathematics, e.g., to the existence of sets, or numbers, or properties, and so on. It is thus explored in some chapters to what extent one’s ontology—and indeed, one’s ontology of necessary beings—interacts with other plausible assumptions and commitments.

An essentialist theory of modality claims that the source of possibility and necessity lies in essence, where essence is then not to be defined in terms of necessity. Hence such theories owe us an account of why it is that the essences of things give rise to necessities in the way required. A new approach to understanding essence in terms of the notion of generalized identity promises to answer this challenge by appeal to the necessity of identity. I explore the prospects for this approach, and argue that it fails. If one favours an account of essence in terms of generalized identity, then one will not, I argue, be able to satisfactorily defend an essentialist theory of modality against the challenge; if one wishes to defend an essentialist theory of modality, and thereby to give an explanation of how necessity arises from essence, one should not understand essence in terms of generalized identity.

In the Postulates of Empirical Thinking, a section of the Critique of Pure Reason, Kant presents an account of the content and role of our concept of real possibility in terms of formal conditions of experience. However, much later in the Critique he introduces the idea of a material condition of possibility. What is this material condition of possibility, and how does it fit with the conception of possibility in terms of formal conditions? This essay argues that the key to answering these questions—as well as to understanding Kant’s criticism of rational theology, in which the discussion of the material condition of possibility appears—is Kant’s account of how we can individuate objects.

What, if any, is the relation between modal judgment and our capacity to make judgments at all? On a plausible interpretation, Kant connects what he calls the modality of a judgment to its location in a course of reasoning: actual inferential relations between that act of judgment and others. There is a puzzling consequence of this interpretation. It is natural to understand Kant as claiming that every judgment has some modality. However, if the modality of a judgment is its location in a course of reasoning, then the implication is that every judgment must occur as part of a course of reasoning. But why think this? In this paper I propose an answer that draws on the relationship between judgment, judging for reasons, and the unity of consciousness.

Recently, a debate has developed between those who claim that essence can be explained in terms of de re modality (modalists), and those who claim that de re modality can be explained in terms of essence (essentialists). The aim of this paper is to suggest that we should reassess. It is assumed that either necessity is to be accounted for in terms of essence, or that essence is to be accounted for in terms of necessity. I will argue that we should assume neither. I discuss what role these key notions – essence and necessity – can reasonably be thought to contribute to our understanding of the world, and argue that, given these roles, there is no good reason to think that we should give an account of one in terms of the other. I conclude: if we can adequately explain de re modality and essence at all, we should aim to do so separately.

What is the function of modal judgment? Why do we make judgments of possibility and necessity? Or are such judgments, in fact, dispensable? This paper introduces and develops an answer to these questions based on Kant’s remarks in section 76 of the Critique of Judgment. Here, Kant appears to argue the following: that a capacity to make modal judgments using modal concepts is required for a capacity for objective representation, in light of our split cognitive architecture. This split cognitive architecture leaves room for a mismatch between our concepts and intuitions and, Kant argues, that is why we need modal concepts and modal judgments. In this paper, I develop this account of the function of modal judgment and to explore the extent to which it may improve upon contemporary alternatives. I focus on one particularly important challenge for the account: to explain why a distinction between the actual and the possible, rather than merely a distinction between the actual and the non-actual, is required. In order to answer this question, I supplement the account with a particular way of thinking about objectivity.

Mental representations—like many other things—seem to have parts. However, it isn’t clear how to properly understand the idea of a part of a representation. In this paper I shed new light on how representations can have a mereology. In particular, it has been recognized that there is a mereological element to Kant’s distinction between two kinds of representations: intuitions and concepts. A concept depends upon its parts, whereas an intuition is prior to its parts. The paper thus focuses on an exploration of how to make sense of the parts and wholes of intuitions and concepts.

Hossack (2007) defends what he calls the rationalist thesis: the thesis that necessity reduces to (or at least always coincides with) a priori knowledge. In this paper I discuss some features of Hossack’s rationalist account of necessity. In the first half, I attempt to fill in a missing link in the rationalist thesis, connecting the notions of primitiveness of facts and a priori modes of presentation. In the second half, I complain that the strategy of dissolving counterexamples is not enough, and that a general principle connecting necessity and a prioricity is needed. I suggest further kinds of counterexamples that might arise, but rather than demand a response to each counterexample, I suggest that they highlight the need for a general argument for the rationalist thesis.