Cathy Legg

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 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.

Charles Peirce famously divided all signs into icons, indices and symbols. As recent decades have seen mainstream analytic philosophy of language broaden its traditional focus on symbols to recognise the "essential indexical", can the moral be extended to icons? Is there an “essential icon”? If so, what exactly would be "essential" about it? I argue that essential iconicity does exist, and a prime example is logical form, insofar as it cannot be discursively described, only 'shown'. Danielle Macbeth’s radical new “expressivist” interpretation of Frege’s logic and Charles Peirce’s existential graphs are mobilized in support of this claim, which offers an original new direction to the foundations of logic.

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).

Integration of ontologies begins with establishing mappings between their concept entries. We map categories from the largest manually-built ontology, Cyc, onto Wikipedia articles describing corresponding concepts. Our method draws both on Wikipedia’s rich but chaotic hyperlink structure and Cyc’s carefully defined taxonomic and common-sense knowledge. On 9,333 manual alignments by one person, we achieve an F-measure of 90%; on 100 alignments by six human subjects the average agreement of the method with the subject is close to their agreement with each other. We cover 62.8% of Cyc categories relating to common-sense knowledge and discuss what further information might be added to Cyc given this substantial new alignment.

Wikipedia is a goldmine of information; not just for its many readers, but also for the growing community of researchers who recognize it as a resource of exceptional scale and utility. It represents a vast investment of manual effort and judgment: a huge, constantly evolving tapestry of concepts and relations that is being applied to a host of tasks. This article provides a comprehensive description of this work. It focuses on research that extracts and makes use of the concepts, relations, facts and descriptions found in Wikipedia, and organizes the work into four broad categories: applying Wikipedia to natural language processing; using it to facilitate information retrieval and information extraction; and as a resource for ontology building. The article addresses how Wikipedia is being used as is, how it is being improved and adapted, and how it is being combined with other structures to create entirely new resources. We identify the research groups and individuals involved, and how their work has developed in the last few years. We provide a comprehensive list of the open-source software they have produced.

This paper seeks an explanation for the challenges faced by Semantic Web developers in achieving their vision, compared to the staggering near-instantaneous success of the World Wide Web. To this end it contrasts two broad philosophical understandings of meaning and argues that the choice between them carries real consequences for how developers attempt to engineer the Semantic Web. The first is Rene Descartes' “private,” static account of meaning (arguably dominant for the last four-hundred years in Western thought), which understands the meanings of signs as whatever their producers intend them to mean. The second is Charles Peirce's still relatively unknown “public,” evolutionary account of meaning, according to which the meaning of signs just is the way they are interpreted and used to produce further signs. It is argued that only the latter approach can avoid the unmanageable attempts to “preprocess” interpretation of signs on the Web that have dogged the project in its many stages, and thereby do justice to the scale, rapid changeability, and exciting possibilities of online information today.

This paper takes indexicality as a case-study for critical examination of the distinction between semantics and pragmatics as currently conceived in mainstream philosophy of language. Both a ‘pre-indexical’ and ‘post-indexical’ analytic formal semantics are examined and found wanting, and instead an argument is mounted for a ‘properly pragmatist pragmatics’, according to which we do not work out what signs mean in some abstract overall sense and then work out to what use they are being put; rather, we must understand to what use signs are being put in order to work out what they mean.