The purpose of this paper is to offer a distinct contribution to recent attempts to understand Peirce’s normative thinking. Scholars have interpreted the real tensions in Peirce’s normative thought by conflating passages from different moments in the development of his philosophy. Extracts from Peirce’s famous 1898 lectures (when he dismissed ethics as useless) are frequently combined with later passages from 1902 onwards, when he changed his mind. This paper proceeds by tracing the growth of Peirce’s thinking about ethics and correlating (...) his conflicting positions with his theory of the categories. The approach offered here is diachronic. A diachronic approach is necessary to correct some efforts to resolve the inconsistencies in Peirce’s moral theory. Also, a categorical account is understood as essential to perceive the inner coherence of his moral philosophy and to support the view that Peirce moved from a nominalist to a realist position in ethics. By connecting Peirce’s conceptions of ethics to his theory of the categories I hope to have provided a better understanding of the structure of his normative realism. (shrink)

Several recent publications attest to a renewed interest, at the dawn of the 21st century, in the philosophy of Charles S. Peirce. While agreeing with the relevance of Peirce philosophy for the 21st century, we disagree with some interpretations of Peirce as a utilitarian-based pragmatist, or with attempts to extract from Peirce a theory of social justice for 21st century societies. A critical exploration of Peirce’s philosophy of science, particularly his idea of scientific inquiry as “the study of useless things”, (...) serves to illuminate the un-pragmatic and anti-utilitarian dimension of Peirce’s thought, as well as to reveal his true ethical relevance for the 21st century. (shrink)

: In 1878's ‘How to Make Our Ideas Clear’, Peirce states that truth is the predestinate opinion, or that which is fated to be ultimately agreed to by all who investigate. Later in his life, though, he would claim both that truth is what would be believed if we could figure out the right method of inquiry and that, instead of affirming that truth is the predestinate opinion in 1878, he ought to have affirmed that truth is what would be (...) believed if inquiry were carried sufficiently far. The aim of this paper is to provide an account of why the early Peirce endorses the claim that truth is the predestinate opinion and why the late Peirce is compelled to modify that position. I argue that Peirce's early statement that truth is the predestinate opinion is motivated by his theory that all mental action is of the nature of a valid inference and that the later modification of his view is partly motivated by his rejection of that theory. (shrink)

Louis Loeb has argued that Hume is pessimistic while Peirce is optimistic about the attainment of fully stable beliefs. In contrast, we argue that Hume was optimistic about such attainment but only if the scope of philosophical investigation is limited to first-order explanatory questions. Further, we argue that Peirce, after reformulating the pragmatic maxim to accommodate the reality of counterfactuals, was pessimistic about such attainment. Finally, we articulate and respond to Peirce's objection that Hume's skeptical arguments in T 1.4.1 and (...) his commitment to common sense indicate that Hume was confused about whether we could have stable beliefs at all. (shrink)

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)

Development of decision-support and intelligent agent systems necessitates mathematical descriptions of uncertainty and fuzziness in order to model vagueness. This paper seeks to present an outline of Peirce’s triadic logic as a practical new way to model vagueness in the context of artificial intelligence. Charles Sanders Peirce was an American scientist–philosopher and a great logician whose triadic logic is a culmination of the study of semiotics and the mathematical study of anti-Cantorean model of continuity and infinitesimals. After presenting Peircean semiotics (...) within AI perspective, a mathematical formulation of a Peircean triadic set is given in relationship with classical and fuzzy sets. Using basic logical operators, all possible respective implication operators, bi-equivalence operators, valid rules of inference, and associative, distributive and commutative logical properties are derived and verified through the truth function approach. In order to suggest practical directions, aggregation operators for Peirce’s triadic logic have been formulated. A mathematical formulation of a medical diagnostic problem and ER diagram of a library management system using Peirce’s triadic relation show potential for further applications of the proposed triadic set and triadic logic. Alongside, a classical AI game—The Wumpus World—is implemented to show practical efficacy in comparison with binary implementation. Besides giving some preliminary formulations for trichotomous set theory and definition of finite automaton, development of hybrid architectures for intelligent agents and evolutionary computations are discussed as potential practical avenues for Peirce’s triadic logic. (shrink)

Since the pioneering work by Kripke and Montague, the term possible world has appeared in most theories of formal semantics for modal logics, natural languages, and knowledge-based systems. Yet that term obscures many questions about the relationships between the real world, various models of the world, and descriptions of those models in either formal languages or natural languages. Each step in that progression is an abstraction from the overwhelming complexity of the world. At the end, nothing is left but a (...) colorful metaphor for an undefined element of a set W called worlds, which are related by an undefined and undefinable primitive relation R called accessibility. For some purposes, the resulting abstraction has proved to be useful, but as a general theory of meaning, the abstraction omits too many significant features. So much information has been lost at each step that many philosophers, linguists, and psychologists have dismissed model-theoretic semantics as irrelevant to the study of meaning. This article examines the steps in the process of extractingthe pair (W,R) from the world and the way people talk about the world. It shows that the Kripke worlds can be reinterpreted as part of a Peircean semiotic theory, which can also include contributions from many other studies in cognitive science. Among them are Dunn’s semantics based on laws and facts, the lexical semantics preferred by manylinguists, psychological models of how the world is perceived, and philosophies of science that relate theories to the world. A full integration of all those sources is far beyond the scope of this article, but an outline of the approach suggests that Peirce’s vision is capable of relating and reconciling the competing sources. (shrink)

This is the second of two papers that examine Charles Peirce’s denial that human beings have a faculty of intuition. In the first paper, I argued that in its metaphysical aspect, Peirce’s denial of intuition amounts to the doctrine that there is no determinate boundary between the internal world of the cognizing subject and the external world that the subject cognizes.In the present paper, I argue that, properly understood, the “objective idealism” of Peirce’s 1890s cosmological series is a more general (...) iteration of the metaphysical aspect of his earlier denial of intuition. I also consider whether Peirce continued to deny that there is a definite boundary between the internal and external worlds in the years after the cosmological series. (shrink)

This paper aims to consider Peirce and Eco’s approach to signs and semiotics in order to assess their relation to Peirce’s mature pragmatism. Both thinkers attempted to set out a truly general theory of signs, and ran into difficulties on similar points. I show that the responses of Peirce and Eco to the difficulties that arose in seeking a truly general theory of signs were quite different. And yet, the differences are not so deep as to prevent us from thinking (...) of both Peirce and Eco as pragmatists, and perhaps of a similar stripe. (shrink)

A cluster of similar trends emerging in separate fields of science and philosophy points to new opportunities to apply biosemiotic ideas as tools for conceptual integration in theoretical biology. I characterize these developments as the outcome of a “relational turn” in these disciplines. They signal a shift of attention away from objects and things and towards relational structures and processes. Increasingly sophisticated research technologies of molecular biology have generated an enormous quantity of experimental data, sparking a need for relational approaches (...) that could help to find recurrent patterns in the mass of data. Earlier conceptions of relational biology and cybernetics, once deemed too abstract and speculative, are now resurrected and applied by means of new computational and simulation tools. I think this receptivity should be extended to incorporate nets of semiotic relations as heuristic guides for discerning global patterns of interactions in living systems. In this article I review aspects of systems biology and new directions in evolutionary theory, focusing on the role of circular and downward causation in relational structures and dynamical networks. I also indicate promising avenues of integration of some ideas of biosemiotics with those emerging from these new currents in biology. Relational developments in biology bear a telling similarity to a parallel relational turn presently manifest in the philosophy of science, rooted in the philosophy of physics and mathematics and in different varieties of structural and informational realism. The recognition of the relational nature of reality within these disciplines entails a tacit repudiation of nominalistic biases in science that have hindered the reception of semitiotic conceptions in biology. In previous investigations I explored connections between two kinds of relational structures: the networks of self-referential circular loops that appear pervasively in living systems, and the triadic relational structures that Peircean semiotics places at the basis of all semiotic transactions. Current relational views in the sciences seem oblivious to the difference between dyadic and triadic relations. Incorporating this essential distinction from biosemiotics into other fields could be a first step in seizing the opportunities opened by the relational turn for a renewal of biology and of natural philosophy in general, across disciplinary boundaries. (shrink)

O pragmatismo, como método formal, nos fornece uma importante arena para discussões a respeito do modo pelo qual conceitos podem ser construídos, independentemente de qualquer posição antropocêntrica ou linguística. O presente trabalho tem por finalidade efetuar uma discussão sobre a máxima pragmática e a tese sobre a indeterminação do significado ( meaning ) que ela traz consigo. Ou seja, busca-se entender o trânsito que há entre o indefinido e o definido, entre o indeterminado e o determinado, bem como algumas fronteiras (...) intermediárias encontradas nos processos de determinação relativa do conceito. (shrink)

In 1898 C. S. Peirce declares that the medieval doctrine of consequences had been the starting point of his logical investigations in the 1860s. This paper shows that Peirce studied the scholastic theory of consequentiae as early as 1866–67, that he adopted the scholastics’ terminology, and that that theory constituted a source of logical doctrine that sustained Peirce for a lifetime of creative and original work.

In 1909, Peirce recorded in a few pages of his logic notebook some experiments with matrices for three-valued propositional logic. These notes are today recognized as one of the first attempts to create non-classical formal systems. However, besides the articles published by Turquette in the 1970s and 1980s, very little progress has been made toward a comprehensive understanding of the formal aspects of Peirce's triadic logic (as he called it). This paper aims to propose a new approach to Peirce's matrices (...) for three-valued propositional logic. We suggested that his logical matrices give rise to three different systems, one of them - which we called P3 - is an original and non-explosive logic. Besides that, we will show that the P3 system can easily be transformed into paraconsistent and paracomplete calculi, adding to it, respectively, unary operators of consistency and intuitionistic negation. We conclude with a discussion about philosophical motivations. (shrink)