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. (shrink)

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. (shrink)

Robert Brandom’s expressivism argues that not all semantic content may be made fully explicit. This view connects in interesting ways with recent movements in philosophy of mathematics and logic (e.g. Brown, Shin, Giaquinto) to take diagrams seriously - as more than a mere “heuristic aid” to proof, but either proofs themselves, or irreducible components of such. However what exactly is a diagram in logic? Does this constitute a semiotic natural kind? The paper will argue that such a natural kind does (...) exist in Charles Peirce’s conception of iconic signs, but that fully understood, logical diagrams involve a structured array of normative reasoning practices, as well as just a “picture on a page”. (shrink)

Charles S. Peirce’s semiotics uniquely divides signs into: i) symbols, which pick out their objects by arbitrary convention or habit, ii) indices, which pick out their objects by unmediated ‘pointing’, and iii) icons, which pick out their objects by resembling them (as Peirce put it: an icon’s parts are related in the same way that the objects represented by those parts are themselves related). Thus representing structure is one of the icon’s greatest strengths. It is argued that the implications of (...) scaffolding education iconically are profound: for providing learners with a navigable road-map of a subject matter, for enabling them to see further connections of their own in what is taught, and for supporting meaningful active learning. Potential objections that iconic teaching is excessively entertaining and overly susceptible to misleading rhetorical manipulation are addressed. (shrink)

Much mainstream analytic epistemology is built around a sceptical treatment of modality which descends from Hume. The roots of this scepticism are argued to lie in Hume’s (nominalist) theory of perception, which is excavated, studied and compared with the very different (realist) theory of perception developed by Peirce. It is argued that Peirce’s theory not only enables a considerably more nuanced and effective epistemology, it also (unlike Hume’s theory) does justice to what happens when we appreciate a proof in mathematics.

Charles Peirce famously divided all signs into icons, indices and symbols. The past few decades have seen mainstream analytic philosophy broaden its traditional focus on symbols to recognise the so-called essential indexical. Can the moral now be extended to icons? Is there an “essential icon”? And if so, what exactly would be essential about it? It is argued that there is and it consists in logical form. Danielle Macbeth’s radical new “expressivist” interpretation of Frege’s logic and Charles Peirce’s existential graphs (...) are mobilized in support of this claim. (shrink)

Neopragmatism has been accused of having ‘an experience problem’. This paper begins by outlining Hume's understanding of perception according to which ideas are copies of impressions thought to constitute a direct confrontation with reality. This understanding is contrasted with Peirce's theory of perception according to which percepts give rise to perceptual judgments which do not copy but index the percept (just as a weather-cock indicates the direction of the wind). Percept and perceptual judgment thereby mutually inform and correct one another, (...) as the perceiver develops mental habits of interpreting their surroundings, so that, in this theory of perception, as Peirce puts it: “[n]othing at all…is absolutely confrontitional”. Paul Redding has argued that Hegel’s “idealist understanding of logical form” ran deeper than Kant’s in recognising that Mind is essentially embodied and located, and therefore perspectival. Peirce’s understanding arguably dives deeper still in distributing across the space of reasons (and thus Being) not just Mind’s characteristic features of embodiedness and locatedness, but also its infinite corrigibility. (shrink)

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. (shrink)

The somewhat old-fashioned concept of philosophical categories is revived and put to work in automated ontology building. We describe a project harvesting knowledge from Wikipedia’s category network in which the principled ontological structure of Cyc was leveraged to furnish an extra layer of accuracy-checking over and above more usual corrections which draw on automated measures of semantic relatedness.

An introduction to cat metaphysics..........

Necessity is a touchstone issue in the thought of Charles Peirce, not least because his pragmatist account of meaning relies upon modal terms. We here offer an overview of Peirce’s highly original and multi-faceted take on the matter. We begin by considering how a self-avowed pragmatist and fallibilist can even talk about necessary truth. We then outline the source of Peirce’s theory of representation in his three categories of Firstness, Secondness and Thirdness, (monadic, dyadic and triadic relations). These have modal (...) purport insofar as the first category corresponds to possibility, the second to mechanical necessity and the third to a kind of semantic or intentional necessity. We then turn to Peirce’s explicit modal epistemology and show how it began as information-relative, with different modalities (e.g. logical, physical, practical) distinguished in terms of respective ‘designated states of information’, and shifted later in his life towards a more robust realism founded in direct perception of ideas in their relations. We then turn to Peirce’s formal logic, focusing on his diagrammatic system of Existential Graphs where he did his most serious logical research. Finally we discuss Peirce’s modal metaphysics and its implications for determinism and realism about universals. (shrink)

Would be fairer to call Peirce’s philosophy of language “extensionalist” or “intensionalist”? The extensionalisms of Carnap and Quine are examined, and Peirce’s view is found to be prima facie similar, except for his commitment to the importance of “hypostatic abstraction”. Rather than dismissing this form of abstraction (famously derided by Molière) as useless scholasticism, Peirce argues that it represents a crucial (though largely unnoticed) step in much working inference. This, it is argued, allows Peirce to transcend the extensionalist-intensionalist dichotomy itself, (...) through his unique triadic analysis of reference and meaning, by transcending the distinction between (as Quine put it) “things” and “attributes”. (shrink)

A review of the life and work of the Australian philosopher Huw Price.

The word “hacker” has an interesting double meaning: one vastly more widespread connotation of technological mischief, even criminality, and an original meaning amongst the tech savvy as a term of highest approbation. Both meanings, however, share the idea that hackers possess a superior ability to manipulate technology according to their will (and, as with God, this superior ability to exercise will is a source of both mystifying admiration and fear). This book mainly concerns itself with the former meaning. To Thomas (...) this simultaneously mystified and vilified, elusive set of individuals exemplifies “the performance of technology” xx), showing the way in which “the cultural, social and political history of the computer...is fraught with complexity and contradictions” ix). In fact, he claims that hacking is more a cultural than technological phenomenon, citing Heidegger’s, “[t]he essence of technology is not anything technological” (56). (shrink)

The philosophy of Charles S. Peirce (1839–1914) enhances our understanding of educational processes.

Whereas Charles Peirce’s pragmatist account of truth has been much discussed, his theory of perception still offers a rich mine of insights. Peirce presented a ‘two-ply’ view of perception, which combines an entirely precognitive ‘percept’ with a ‘perceptual judgment’ that is located in the space of reasons. Having previously argued that Peirce outdoes Robert Brandom in achieving a hyper-inferentialism (“Making it Explicit and Clear”, APQ, 2008), I now wish to examine his philosophy in the light of inferentialism’s ‘original fount’ – (...) Wilfrid Sellars. Does Peirce’s percept commit him to the Myth of the Given? I argue that it does not, because although the percept is understood as nonepistemic, it is not understood to justify the perceptual judgment. Rather, the perceptual judgement indexes the percept. I explain this original view, then argue that Peirce and Sellars actually have a great deal in common in their rare diachronically mediated yet at the same time direct perceptual realism, and the ‘critical commonsensist’ epistemology to which it gives rise. (shrink)

This book, officially a contribution to the subject area of Charles Peirce’s semiotics, deserves a wider readership, including philosophers. Its subject matter is what might be termed the great question of how signification is brought about (what Peirce called the ‘riddle of the Sphinx’, who in Emerson’s poem famously asked, ‘Who taught thee me to name?’), and also Peirce’s answer to the question (what Peirce himself called his ‘guess at the riddle’, and Freadman calls his ‘sign hypothesis’).

Book Information Reading Peirce Reading. By Richard A. Smyth. Rowman and Littlefield. Maryland. 1997. Pp. ix + 327. Hardback, US$64.50. Paperback, US$24.95.

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’. (shrink)

Although certain recent developments in mendacious political manipulation of public discourse are horrifying to the academic mind, I argue that we should not panic. Charles Peirce’s pragmatist epistemology with its teleological arc, long horizon, and rare balance between robust realism and contrite fallibilism offers guidance to weather the storm, and perhaps even see it as inevitable in our intellectual development. This paper explores Peirce’s classic “four methods of fixing belief”, which takes us on an entertaining and still very pertinent tour (...) through tenacity, authority and a priori speculation to the method of science – the only method which is both public and self-correcting. Although in the West we (mostly) proudly self-conceive as living in a ‘scientific age’, I argue that this is premature. Precisely insofar as we treat the misbehavior of governments as a harbinger of doom, we remain trapped in authoritarian modes of thinking which Peirce identified with medievalism, although modernity is increasingly quickening around us in worldwide information-sharing practices that are shaped entirely by mutual help. With this framework in mind, many tactics of recent media are most helpfully seen as belonging not to a post-truth, but a pre-truth stage of human intellectual development. Advice on this is sought from Plato, who of course also faced a world that was ‘pre-academic’. (shrink)

This paper offers an expressivist account of logical form, arguing that in order to fully understand it one must examine what valid arguments make us do (or: what Achilles does and the Tortoise doesn’t, in Carroll’s famed fable). It introduces Charles Peirce’s distinction between symbols, indices and icons as three different kinds of signification whereby the sign picks out its object by learned convention, by unmediated indication, and by resemblance respectively. It is then argued that logical form is represented by (...) the third, iconic, kind of sign. It is noted that icons uniquely enjoy partial identity between sign and object, and argued that this holds the key to Carroll’s puzzle. Finally, from this examination of sign-types metaphysical morals are drawn: that the traditional foes metaphysical realism and conventionalism constitute a false dichotomy, and that reality contains intriguingly inference-binding structures. (shrink)