We present a category-theoretical analysis, based on the concept of generic figures, of a diagrammatic system for propositional logic ). The straightforward construction of a presheaf category \ of cuts-only Existential Graphs provides a basis for the further construction of the category \ which introduces variables in a reconstructedly generic, or label-free, mode. Morphisms in these categories represent syntactical embeddings or, equivalently but dually, extensions. Through the example of Peirce’s system, it is shown how the generic figures approach facilitates the (...) formal investigation of relations between syntax and semantics in such diagrammatic systems. (shrink)

This article addresses the problem of the nature of mental imagery from a new perspective. It suggests that sign-theoretical approach as elaborated by C. S. Peirce can give a better and more comprehensive explanation of mental imagery. Our empirical findings follow the methodology of cognitive semiotics and they show that (i) properties of mental images are heterogeneous in nature; (ii) properties of mental images are dependent on the characteristics of object-stimulus; (iii) properties of mental images are dependent on individual differences (...) in imaginary capacities. This suggests that, contrary to representational accounts, mental imagery is not based on one dominant representational format. Imagery constitutes a complex system of signs consisting of several sign elements and dynamic relations. A sign-theoretical account may give a better explanation of the nature of mental imagery, as it accommodates heterogenous evidence from this experiment. (shrink)

One of the leading concerns animating current philosophy of mind is that, no matter how good a scientific account is, it will leave out what its like to be conscious. The challenge has thus been to study or at least explain away that qualitative dimension. Pursuant with that aim, I investigate how philosophy of signs in the Peircean tradition can positively reshape ongoing debates. Specifically, I think the account of iconic or similarity-based reference we find in semiotic theory offers a (...) more promising variant of the phenomenal concept strategy. Philosophers who endorse this strategy think that the difficulties we have fitting conscious qualia into a scientific picture may owe to the peculiar nature of indexical concepts. They point to the fact that, when we try to convey the feel of our experiences, we employ context-dependent gestures and/or utterances that are indexed to perspectives unique to each person. However, according to the theory I defend, there are three ways signs can refer, namely by convention, causal contact, and similarity. Since similarity is not reducible to proximity, I argue that a theory of reference that turns on shared quality can bypass some of the implausible consequences that plague indexical accounts. In the first chapter, I describe the apparatus needed to make sense of this claim. In the second chapter, I present my account of iconic reference. In the third chapter, I justify my reliance on a distinction that is less than real yet more than nominal. In the fourth chapter, I sketch a trinitarian metaphysics well-suited to house the foregoing account of qualia. (shrink)

We present a category-theoretical analysis, based on the concept of generic figures, of a diagrammatic system for propositional logic (Peirce’s Existential Graphs α\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document}). The straightforward construction of a presheaf category EGα∗\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\mathcal {E}}}{{\mathcal {G}}}_{\alpha ^{*}}$$\end{document} of cuts-only Existential Graphs (equivalent to the well-studied category of finite forests) provides a basis for the further construction of the category EGα\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} (...) \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\mathcal {E}}}{{\mathcal {G}}}_\alpha $$\end{document} which introduces variables in a reconstructedly generic, or label-free, mode. Morphisms in these categories represent syntactical embeddings or, equivalently but dually, extensions. Through the example of Peirce’s system, it is shown how the generic figures approach facilitates the formal investigation of relations between syntax and semantics in such diagrammatic systems. (shrink)

Kelly suggested that it was useful to consider anyone as functioning as a scientist, in the business of applying theories, making hypotheses and predictions and testing them out in the practice of everyday life. One of Charles Peirce’s major contributions was to develop the disciplines of logic and the philosophy of science. We can deepen and enrich our understanding of Kelly’s vision by looking at what Peirce has to say about the process of science. For Peirce, the essence of science (...) was the application of the laws of inference. He developed a much broader concept of logic, elaborating the processes of deduction and induction and adding to these the logic of hypothetical inference, or ‘abduction’, even as Kelly broadened it further in his “departure from classical logic”. Examining the implications of these three forms of inference allows us to elaborate the dynamics involved in the process of construing, ordinacy and the cycles of experience, creativity and decision making. This is the second of a three part series examining the relationship between the work of Peirce and Kelly. The third will include a look at phenomenology, bipolarity, the self, dialogical process and sociological considerations. (shrink)

This paper examines the contemporary philosophical and cognitive relevance of Charles Peirce's diagrammatic logic of existential graphs (EGs), the ‘moving pictures of thought’. The first part brings to the fore some hitherto unknown details about the reception of EGs in the early 1900s that took place amidst the emergence of modern conceptions of symbolic logic. In the second part, philosophical aspects of EGs and their contributions to contemporary logical theory are pointed out, including the relationship between iconic logic and images, (...) the problem of the meaning of logical constants, the cognitive economy of iconic logic, the failure of the Frege–Russell thesis, and the failure of the Language of Thought hypothesis. (shrink)

Peirce believed that his pragmaticism can be conclusively proven. Beginning in 1903, he drafted several attempts, ending by 1908 with a semeiotic proof. Around 1905, he exposes the proof using the theory of Existential Graphs . This paper modernizes the semantics Peirce proposed for EGs in terms of game-theoretic semantics . Peirce's 1905 proof is then reconstructed in three parts, by relating pragmaticism to the GTS conception of meaning, showing that Peirce's proof is an argument for a relational structure of (...) the meaning of intellectual signs that our interpretative and strategic practices give rise to, and bringing out the key links between EGs and pragmaticism. (shrink)