Cathy Legg

Much discussion of meaning by philosophers over the last 300 years has been predicated on a Cartesian first-person authority (i.e. “infallibilism”) with respect to what one’s terms mean. However this has problems making sense of the way the meanings of scientific terms develop, an increase in scientific knowledge over and above scientists’ ability to quantify over new entities. Although a recent conspicuous embrace of rigid designation has broken up traditional meaning-infallibilism to some extent, this new dimension to the meaning of terms such as “water” is yet to receive a principled epistemological undergirding (beyond the deliverances of “intuition” with respect to certain somewhat unusual possible worlds). Charles Peirce’s distinctive, naturalistic philosophy of language is mined to provide a more thoroughly fallibilist, and thus more realist, approach to meaning, with the requisite epistemology. Both his pragmatism and his triadic account of representation, it is argued, produce an original approach to meaning, analysing it in processual rather than objectual terms, and opening a distinction between “meaning for us”, the meaning a term has at any given time for any given community and “meaning simpliciter”. the way use of a given term develops over time (often due to a posteriori input from the world which is unable to be anticipated in advance). This account provocatively undermines a certain distinction between “semantics” and “ontology” which is often taken for granted in discussions of realism.

Wittgenstein's discussion of rule‐following is widely regarded to have identified what Kripke called “the most radical and original sceptical problem that philosophy has seen to date”. But does it? This paper examines the problem in the light of Charles Peirce's distinctive scientific hierarchy. Peirce identifies a phenomenological inquiry which is prior to both logic and metaphysics, whose role is to identify the most fundamental philosophical categories. His third category, particularly salient in this context. pertains to general predication. Rule‐following scepticism, the paper suggests, results from running together two questions: “How is it that I can project rules?”, and, “What is it for a given usage of a rule to be right?”. In Peircean terms the former question, concerning the irreducibility of general predication (to singular reference), must be answered in phenomenology, while the latter, concerning the difference between true and false predication, is answered in logic. A failure to appreciate this distinction, it is argued, has led philosophers to focus exclusively on Wittgenstein's famous public account of rule‐following rightness, thus overlooking a private, phenomenological dimension to Wittgenstein's remarks on following a rule which gives the lie to Kripke's reading of him as a sceptic.

This article explores how Robert Brandom's original “inferentialist” philosophical framework should be positioned with respect to the classical pragmatist tradition. It is argued that Charles Peirce's original attack (in “Questions Concerning Certain Faculties Claimed for Man” and other early papers) on the use of “intuition” in nineteenth‐century philosophy of mind is in fact a form of inferentialism, and thus an antecedent relatively unexplored by Brandom in his otherwise comprehensive and illuminating “tales of the mighty dead.” However, whereas Brandom stops short at a merely “strong” inferentialism, which admits some non‐inferential mental content (although it is parasitic on the inferential and can only be “inferentially articulated”), Peirce embraces a total, that is, “hyper‐,” inferentialism. Some consequences of this difference are explored, and Peirce's more thoroughgoing position is defended.

It seems possible to know that a mathematical claim is necessarily true by inspecting a diagrammatic proof. Yet how does this work, given that human perception seems to just (as Hume assumed) ‘show us particular objects in front of us’? I draw on Peirce’s account of perception to answer this question. Peirce considered mathematics as experimental a science as physics. Drawing on an example, I highlight the existence of a primitive constraint or blocking function in our thinking which we might call ‘the hardness of the mathematical must’. This is a 3-page abstract for the DIAGRAMS2018 conference, summarising prior work in papers such as (“Things Unreasonably Compulsory”, Cognitio 15 (1): 89-112 (2014), and "The Hardness of the Iconic Must", Philosophia Mathematica 20 (1): 1-24 (2012)).

Early artificial intelligence research was dominated by intellectualist assumptions, producing explicit representation of facts and rules in “good old-fashioned AI”. After this approach foundered, emphasis shifted to deep learning in neural networks, leading to the creation of Large Language Models which have shown remarkable capacity to automatically generate intelligible texts. This new phase of AI is already producing profound social consequences which invite philosophical reflection. This paper argues that Charles Peirce’s philosophy throws valuable light on genAI’s capabilities first with regard to meaning, then knowledge and truth. Firstly, I explore how Peirce’s icon/index/symbol distinction illuminates the functioning of genAI. I argue that genAI’s engineers have skilfully captured a form of symbolicity, but no other sign-kind. In lacking indexical signs, LLMs lack connection with, and accountability to, particular worldly objects. In lacking iconic signs, LLMs are insufficiently disciplined by structural – most notably logical – relationships. Then I argue that GenAI’s astounding stream of articulate, truth-semblant, yet worthless texts issues a timely reckoning to modern philosophy’s representational realism. By contrast, Peirce’s pragmatism scaffolds a rich relational realism (Gili and Maddalena 2022), which shows how meaningful concepts, and a grasp of truth, can only occur across multiple cognitive systems who are simultaneously richly related with one another, and a shared environment in which they continually act and receive feedback, within a logical space of reasons. As Peirce himself noted, “Mere knowledge, though it be systematized, may be a dead memory; while by science we all habitually mean a living and growing body of truth”.

We discuss the one–many problem as it appears in the Philebus and find that it is not restricted to the usually understood problem about the identity of universals across particulars that instantiate them (the Hylomorphic Dispersal Problem). In fact some of the most interesting aspects of the problem occur purely with respect to the relationship between Forms. We argue that contemporary metaphysicians may draw from the Philebus at least three different one–many relationships between universals themselves: instantiation, subkind and part, and thereby construct three new ‘problems of the one and the many’ (an Eidetic Dispersal Problem, a Genus–Species Problem, and an Eidetic Combination Problem), which are as problematic as the version generally discussed. We then argue that this taxonomy sheds new and interesting light on certain discussions of higher-order universals in recent Australian analytic philosophy.

Charles Peirce's diagrammatic logic — the Existential Graphs — is presented as a tool for illuminating how we know necessity, in answer to Benacerraf's famous challenge that most ‘semantics for mathematics’ do not ‘fit an acceptable epistemology’. It is suggested that necessary reasoning is in essence a recognition that a certain structure has the particular structure that it has. This means that, contra Hume and his contemporary heirs, necessity is observable. One just needs to pay attention, not merely to individual things but to how those things are related in larger structures, certain aspects of which relations force certain other aspects to be a certain way

Despite some notable similarities between the scientific realisms of Sellars and Peirce (such as both being anti-representationalist, and future-directed), in his mature work Science and Metaphysics Sellars explicitly critiqued Peirce’s account of truth, as lacking “an intelligible foundation” (Sellars 1968: vii). In this paper, I explore Sellars’ proposed remedy to Peirce’s purported lack, in his complex and enigmatic account of picturing – a non-discursive ‘mapping’ of the world. I argue that although Sellars’ development of this idea is largely sound, much of what he charges Peirce’s philosophy with missing is actually present there. By means of his semiotic icon / index / symbol distinction, Peirce manages to develop a philosophy of language which effectively coordinates the real order and the order of signification within the very structure of the proposition as he understands it, by contrast to Sellars’ claim that the two orders are merely connected through ‘analogy’. I also argue that in between Sellars’ ambitious account of veridicality, which appears to anticipate a form of scientific self-mensuration, and the dismissive ‘anti-truth’ quietism of neopragmatists such as Rorty, Peirce’s “contrite fallibilism” (Peirce CP 1.14) charts a wise middle path.

Pragmatism is a philosophical tradition that understands knowing the world as inseparable from agency within it. It thereby introduces some unique ideas and approaches to the analysis of concepts. Looking largely to pragmatism’s founder, Charles Peirce, this chapter presents an account of concepts as habits which associate specific kinds of environmental stimuli with schemata of action and ensuing experience, within linguistic communities. I explain how this account avoids Sellars’ ‘Myth of the Given’. I then explore how Peirce’s semiotic approach to philosophy of language and mind theorized signifying habits as symbols which draw icons and indices together into propositional structures, thereby generating meanings that are specifically applicable and indefinitely generalizable. This original account of concept formation is further illuminated through an examination of Peirce’s philosophy of perception, which makes particularly manifest the process whereby primitive indices, or ‘percepts’, are enfolded in symbolic meanings through habitual ‘perceptual judgements’.

Wilfrid Sellars’ distinctive scientific realism has lately been gaining ground, but a crucial issue is how it can or should theorize modality. We argue that many interesting questions in this area transcend the usual ‘first-order’ concerns: “Is there an objectivist modal ontology?” and “What modal entities should we posit”? Rather, Sellars invites us to take a fresh look at the relationship between logic and metaphysics through an investigation of ‘second-order’ philosophical categories. This investigation contrasts with both the first-order 'external' ontologising of metaphysicians such as David Lewis and the 'easy' ontologising of metaphysicians such as Amie Thomasson. We argue that Sellars' approach stimulates a more conscious and fruitful examination of our role and methods as philosophers in the modal arena. Moreover, since the notion of metaphysics as a ‘second-order’ activity has recently gained attention in contemporary philosophy of science through the work of David Wallace, we explore both Sellars’ potential contribution to these discussions and the relationship between Sellars’ approach and contemporary ontic structural realist views regarding modal structure, thereby opening up fundamental questions concerning where and how the metaphysics of modality might be integrated with our current best physics. 

The “four-dimensional” colour space pigeons see may contain millions more colours than ours. Despite the long history of close association between our species, we might say humans and pigeons live in quite different worlds. If different species effectively live in different worlds, does that mean our biology constructs reality? This article sketches a way to resolve this dilemma based on inquiry and action as theorised by pragmatist philosopher Charles Peirce. It reports on an academic paper recently published by my colleague Andre Sant’Anna and myself. (“Pragmatic Realism: Towards a Reconciliation of Enactivism and Realism”, Phenomenology and the Cognitive Sciences, Feb 2024).

How is it that false statements, such as “horses have eight legs”, can be just as meaningful as true statements, such as “horses have four legs”? Where does logical structure come from? We can describe what the world would be like if the laws of physics were different – could we do the same for the laws of logic? Are there facts about ethics? If we ever managed to answer the philosophical questions that humans have pondered for thousands of years, what would life look like on the other side? All of these questions and more are addressed in Ludwig Wittgenstein’s early work, the Tractatus Logico-Philosophicus…which was first published 100 years ago.

This piece ponders how teachers might best approach the issue of truth in the classroom, now that traditional models of truth-transmission have been problematised by what social epistemologist Steven Fuller calls ‘second-order awareness’—the apparent social construction of any given ‘truth-game’. Drawing on Charles Peirce’s original theorisation of the ‘community of inquiry’ at the birth of pragmatist philosophy, I argue that, as educators our best response to the recent ‘post-truth’ phenomenon is to pay less attention to our theories, in which we show up to truth-sceptics as experts, and more attention to our own epistemic practices, in which we show up to truth-sceptics as fellow persons. In any real-world encounter between persons, genuine listening and learning can offer practical proof that truth is not dead, notwithstanding the dire theoretical generalisations of sceptics, nihilists and relativists. I conclude by reflecting on some ways I’ve implemented these insights in developing a new first-year undergraduate Critical Thinking unit at my own university.

In order to achieve genuine web intelligence, building some kind of large general machine-readable conceptual scheme (i.e. ontology) seems inescapable. Yet the past 20 years have shown that manual ontology-building is not practicable. The recent explosion of free user-supplied knowledge on the Web has led to great strides in automatic ontology building, but quality-control is still a major issue. Ideally one should automatically build onto an already intelligent base. We suggest that the long-running Cyc project is able to assist here. We describe methods used to add 35K new concepts mined from Wikipedia to collections in ResearchCyc entirely automatically. Evaluation with 22 human subjects shows high precision both for the new concepts’ categorization, and their assignment as individuals or collections. Most importantly we show how Cyc itself can be leveraged for ontological quality control by ‘feeding’ it assertions one by one, enabling it to reject those that contradict its other knowledge.

This paper explores how Charles Peirce’s habit-based epistemology leads him to theorise perception. I show how Peirce’s triadic semiotic analysis of perceptual judgment renders his theory of perception neither a representationalism nor a relationism /direct realism, but an interesting hybrid of the two. His view is also extremely interesting, I argue, in the way that by analysing symbols as habits it refuses the common assumption that perception is an affair best understood synchronically, as a ‘language-entry event’. Relatedly, I extend previous work (Legg 2008) which argues that Peirce’s epistemology counts as a ‘hyperinferentialism’ in Robert Brandom’s terms, but this does not mean that Peirce’s theory of perception cannot accommodate unmediated contact with reality - what Peirce called ‘the outward clash’.

This paper addresses some apparent philosophical tensions between realism and enactivism by means of Charles Peirce’s pragmatism. Enactivism’s Mind-Life Continuity thesis has been taken to commit it to some form of anti-realist ‘world-construction’ which has been considered controversial. Accordingly, a new realist enactivism is proposed by Zahidi (Phenomenology and the Cognitive Sciences 13(3), 2014), drawing on Ian Hacking’s ‘entity realism’, which places subjects in worlds comprised of the things that they can successfully manipulate. We review this attempt, and argue that whilst Zahidi rightly urges enactivists towards ‘internal realism’, he cannot sustain a non-negotiable aspect of realism that is crucial for scientific progress – the claim that multiple subjects inhabit the same world. We explore Peirce’s pragmatism as an alternative solution, foregrounding his distinction between existence and reality, and his inquiry-based account of cognition. These theoretical innovations, we argue, fruitfully generalize Zahidi’s manipulation-based enactivist realism to a richer, inquiry-based enactivist realism. We explore how this realism’s pan-species monism about truth encourages and supports the investigation of non-human animal cognition, and conclude by considering some implications of our discussion for long-standing realism debates within pragmatism.

Joseph Ransdell (1931–2010), who received his Ph.D in philosophy from Columbia University in 1966, where he was advised by Sidney Morgenbesser, and spent most of his career at Texas Tech University, offered an original and focused challenge to academic philosophy at the end of the Second Millennium. His guiding philosophical passion was understanding how communication might best encourage and support truth seeking. This introduction to a special edition of the Transactions of the Charles S. Peirce Society which is devoted to Joe's legacy presents his philosophical interests, and the distinctive and valuable role he played in establishing the "Peirce Telecommunity", which has nurtured a range of Peirce scholars outside of the normal institutional frameworks for philosophical research and discussion.

Mainstream philosophy has seen a recent flowering in discussions of intellectualism which revisits Gilbert Ryle’s famous distinction between ‘knowing how’ and ‘knowing that’, and challenges his argument that the former cannot be reduced to the latter. These debates so far appear not to have engaged with pragmatist philosophy in any substantial way, which is curious as the relation between theory and practice is one of pragmatism’s main themes. Accordingly, this paper examines the contemporary debate in the light of Charles Peirce’s habit-based epistemology. We argue both that knowing-that can be understood as a particularly sophisticated form of knowing-how, and that all bodily competencies—if sufficiently deliberately developed—can be analysed as instantiating propositional structure broadly conceived. In this way, intellectualism and anti-intellectualism are seen to be not opposed, and both true, although Peirce’s original naturalistic account of propositional structure does lead him to reject what we shall call ‘linguistic intellectualism’.

Although pragmatism and phenomenology have both contributed significantly to the genealogy of so-called “4E” – embodied, embedded, enactive and extended – cognition, there is benefit to be had from a systematic comparative study of these roots. As existing 4E cognition literature has tended to emphasise one or the other tradition, issues remain to be addressed concerning their commonalities – and possible incompatibilities. We begin by exploring pragmatism and phenomenology’s shared focus on contesting intellectualism, and its key assumption of mindedness as representation. We then outline distinctive insights from both traditions regarding the nature and role of habits, in order to put forward a habit-based epistemology as an alternative to the Cartesian idea-based epistemology that has dominated modern philosophy. We pay particular attention to the work of classical pragmatist C.S. Peirce, arguing that his semiotics, which analyses sign-use as habit, shows how theorists of embodied cognition can break a certain false dichotomy between embodiment and logical or intellectual structure which has prevented them from fully theorising propositional knowledge. In this way, our work both augments and challenges the Dewey/Merleau-Ponty connection that has been much more extensively explored by the field.

In many diagrams one seems to perceive necessity – one sees not only that something is so, but that it must be so. That conflicts with a certain empiricism largely taken for granted in contemporary philosophy, which believes perception is not capable of such feats. The reason for this belief is often thought well-summarized in Hume's maxim: ‘there are no necessary connections between distinct existences’. It is also thought that even if there were such necessities, perception is too passive or localized a faculty to register them. We defend the perception of necessity against such Humeanism, drawing on examples from mathematics.

This poised and articulate volume addresses an area of pragmatist philosophy as yet relatively unexplored in pragmatism's welcome revival. Neopragmatism's preoccupation with changing philosophers' view of the relation between language (or as Rorty puts it: "vocabularies") and reality, has largely focussed their discussions on the 'metaphysics & epistemology', rather than the 'value' side of philosophy, apart from Rorty's brief flirtations with edifying Western political discourse. Yet the nature of truth in ethics has been a topic of keen discussion in recent mainstream philosophy, and it's widely acknowledged that pragmatism has original and interesting things to say about truth. This book seeks to contribute in particular to discussions of objectivity in ethics which are arguably somewhat bogged down in a wealth of finely divergent terminologies and positions: prescriptivism, fictionalism, intuitionism, quasi-realism and expressivism, to name just a few. Heney organises her own discussion around a distinction between cognitivism and non-cognitivism about moral claims.

Enactivism has influentially argued that the traditional intellectualist ‘act-content’ model of intentionality is insufficient both phenomenologically and naturalistically, and minds are built from world-involving bodily habits – thus, knowledge should be regarded as more of a skilled performance than an informational encoding. Radical enactivists have assumed that this insight must entail non-representationalism concerning at least basic minds. But what if it could be shown that representation is itself a form of skilled performance? I sketch the outline of such an account from the perspective of Peirce’s pragmatist semiotics, which theorises signs as habits of associating specific cues with appropriate acts and schemas of ensuing experience. Within this framework, I argue, a naturalistic account of propositional structure can be constructed which transcends the symbolic – and in some instances even the linguistic – sphere, and offers new insights regarding the Information Processing Challenge, and the Hard Problem of Content.

Although most contemporary philosophers of language hold that semantics and pragmatics require separate study, there is surprisingly little agreement on where exactly the line should be drawn between these two areas, and why. In this paper I suggest that this lack of clarity is at least partly caused by a certain historical obfuscation of the roots of the founding three-way distinction between syntax, semantics and pragmatics in Charles Peirce’s pragmatist philosophy of language. I then argue for recovering and revisiting these original roots, taking indexicality as a case-study of how certain questions connected with the distinction which are currently considered complex and difficult may be clarified by a ‘properly pragmatist pragmatics’. Such a view, I shall argue, upends a certain priority usually accorded to semantics over pragmatics, teaching that we do not work out what terms mean in some abstract overall sense and then work out to what use they are being put; rather, we must understand to what use terms are being put in order to understand what they mean.

This paper presents a Peircean take on Wittgenstein's famous rule-following problem as it pertains to 'knowing how to go on in mathematics'. I argue that McDowell's advice that the philosophical picture of 'rules as rails' must be abandoned is not sufficient on its own to fully appreciate mathematics' unique blend of creativity and rigor. Rather, we need to understand how Peirce counterposes to the brute compulsion of 'Secondness', both the spontaneity of 'Firstness' and also the rational intelligibility of 'Thirdness'. (This is a written version of a presentation I gave at the “Peirce’s Mathematics” conference, Universidad Nacional de Colombia, November 25-27, 2015, which was organized by Professor Fernando Zalamea. The piece owes much to the inspiration of Prof. Zalamea's writings on philosophy of mathematics.)

This book constitutes the refereed proceedings of the 12th International Conference on the Theory and Application of Diagrams, Diagrams 2021, held virtually in September 2021. The 16 full papers and 25 short papers presented together with 16 posters were carefully reviewed and selected from 94 submissions. The papers are organized in the following topical sections: design of concrete diagrams; theory of diagrams; diagrams and mathematics; diagrams and logic; new representation systems; analysis of diagrams; diagrams and computation; cognitive analysis; diagrams as structural tools; formal diagrams; and understanding thought processes. 10 chapters are available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

This article is concerned with developing a philosophical approach to a number of significant changes to academic publishing, and specifically the global journal knowledge system wrought by a range of new digital technologies that herald the third age of the journal as an electronic, interactive and mixed-media form of scientific communication. The paper emerges from an Editors' Collective, a small New Zealand-based organisation comprised of editors and reviewers of academic journals mostly in the fields of education and philosophy. The paper is the result of a collective writing process.

Philosophical discussion of truthmaking has flourished in recent times, but what exactly does it mean to ‘make’ a truth-bearer true? I argue that ‘making’ is a concept with modal force, and this renders it a problematic deployment for truthmaker theorists with nominalist sympathies, which characterises most current theories. I sketch the outlines of what I argue is a more genuinely realist truthmaker theory, which is capable of answering the explanatory question: In virtue of what does each particular truthmaker make its particular truthbearer(s) true? I do this by drawing on recent work by Frederik Stjernfelt on Charles Peirce’s account of the proposition as having a ‘particular double structure’, according to which a proposition not only depicts certain characters of an object, it also depicts itself claiming those characters to pertain to the object. This double structure, I shall argue, also resolves important issues in analytic philosophers’ truthmaker theory, including the proper distinction between reference and truthmaking, and a dilemma concerning an infinite regress of truthmaking.