It is commonly supposed that the pragmatisms of Peirce and James are fundamentally opposed; this view is supported by the fact that in 1905 Peirce deliberately chose a new name for his original doctrine. Yet Peirce and James were not only life-long friends but to a surprising extent were life-long collaborators. It is true that their approaches to philosophy were very different, reflecting their distinct personalities, with James exhibiting a pluralistic and humanistic style as opposed to Peirce the analyst and (...) formalist. James was a popular philosopher and Peirce a philosopher for philosophers. But they followed each other’s work, corresponded about philosophical problems, and deeply influenced each other. Peirce never completely renounced James’s broader pragmatism and tried hard to find common ground, even to some extent reshaping his own views to accommodate James’s. (shrink)

The logic of worldviews provides a consistent method of comparison between multiple worldviews. The present paper connects the logic of worldviews to important historical and contemporary influences. Beginning with its roots in semiotics, an account of epistemology emerges which is mediated by a belief system. We show that Charles Peirce’s pragmatistic theory of inquiry is the bedrock beneath the logic of worldviews. We formulate it as a generalized version of inquiry with underlying game-theoretic semantics. In this paper, we extend Peirce’s (...) triadic model of signs to cover knowledge mediated by systems of beliefs. Michael Polanyi’s account of personal commitment includes a subsidiary/focal distinction that views theoretical frameworks as tools for interpreting orders of reality through actual practices of research. We also see how a precedent is set by Johan Georg Hamann’s epistemology of belief, recovered by Ludwig Wittgenstein, using reason as an interpretation of God’s speech in nature. We argue that Thomas Kuhn’s theory of inquiry and worldviews (or paradigms) may be fruitfully contrasted with Peirce’s theory, with reasoning by abduction, deduction, and induction occurring within the community of inquirers. The upshot is that although worldviews may be adopted for non-rational reasons, one can meaningfully compare worldviews through a method proposed by Alasdair MacIntyre: the proponent of a theory learns the language of competing theories and uses them as a metatheory to show how one’s own theory may not have the resources to resolve certain problematic situations. Our result is a meta-linguistic falsification in the sense of Peirce’s semiotics and pragmaticism: the competing theory may be used to show that the object theory does not have a strategy at its disposal to interpret the anomalous phenomenon. (shrink)

This volume presents mathematical game theory as an interface between logic and philosophy.

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)

We describe Peirce’s 1903 system of modal gamma graphs, its transformation rules of inference, and the interpretation of the broken-cut modal operator. We show that Peirce proposed the normality rule in his gamma system. We then show how various normal modal logics arise from Peirce’s assumptions concerning the broken-cut notation. By developing an algebraic semantics we establish the completeness of fifteen modal logics of gamma graphs. We show that, besides logical necessity and possibility, Peirce proposed an epistemic interpretation of the (...) broken-cut modality, and that he was led to analyze constructions of knowledge in the style of epistemic logic. (shrink)