What is a logical diagram?

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”

Commentary on “Demystifying the Influential IS Legends of Positivism”

This commentary questions the argument made in the article, “Demystifying the Influential IS Legends of Positivism” (Siponen & Tsohou, 2018). Contrary to the article, this commentary fully accepts that logical positivism as a school of thought in the philosophy of science has fallen into disrepute, points out that the IS researchers who have characterized positivism in their own ways never said that they were following logical positivism, interprets what these researchers had in mind when characterizing positivism in the ways that they did, and ponders what difference Siponen and Tsohou’s discussion on logical positivism actually makes to the future of IS research

Greek and Roman Logic

In ancient philosophy, there is no discipline called “logic” in the contemporary sense of “the study of formally valid arguments.” Rather, once a subfield of philosophy comes to be called “logic,” namely in Hellenistic philosophy, the field includes (among other things) epistemology, normative epistemology, philosophy of language, the theory of truth, and what we call logic today. This entry aims to examine ancient theorizing that makes contact with the contemporary conception. Thus, we will here emphasize the theories of the “syllogism” in the Aristotelian and Stoic traditions. However, because the context in which these theories were developed and discussed were deeply epistemological in nature, we will also include references to the areas of epistemological theorizing that bear directly on theories of the syllogism, particularly concerning “demonstration.” Similarly, we will include literature that discusses the principles governing logic and the components that make up arguments, which are topics that might now fall under the headings of philosophy of logic or non-classical logic. This includes discussions of problems and paradoxes that connect to contemporary logic and which historically spurred developments of logical method. For example, there is great interest among ancient philosophers in the question of whether all statements have truth-values. Relevant themes here include future contingents, paradoxes of vagueness, and semantic paradoxes like the liar. We also include discussion of the paradoxes of the infinite for similar reasons, since solutions have introduced sophisticated tools of logical analysis and there are a range of related, modern philosophical concerns about the application of some logical principles in infinite domains. Our criterion excludes, however, many of the themes that Hellenistic philosophers consider part of logic, in particular, it excludes epistemology and metaphysical questions about truth. Ancient philosophers do not write treatises “On Logic,” where the topic would be what today counts as logic. Instead, arguments and theories that count as “logic” by our criterion are found in a wide range of texts. For the most part, our entry follows chronology, tracing ancient logic from its beginnings to Late Antiquity. However, some themes are discussed in several eras of ancient logic; ancient logicians engage closely with each other’s views. Accordingly, relevant publications address several authors and periods in conjunction. These contributions are listed in three thematic sections at the end of our entry

Altruism, Jesus and the End of the World—How the Templeton Foundation bought a Harvard Professorship and attacked Evolution, Rationality and Civilization. A review of E.O. Wilson 'The Social Conquest of Earth' (2012) and Nowak and Highfield ‘SuperCooperators’ (2012)

Famous ant-man E.O. Wilson has always been one of my heroes --not only an outstanding biologist, but one of the tiny and vanishing minority of intellectuals who at least dares to hint at the truth about our nature that others fail to grasp, or insofar as they do grasp, studiously avoid for of political expedience. Sadly, he is ending his long career in a most sordid fashion as a party to an ignorant and arrogant attack on science motivated at least in part by religious fervor. It shows the vile consequences when universities accept money from religious groups, science journals are so awed by big names that they avoid proper peer review, and when egos are permitted to get out of control. It takes us into the nature of evolution, the basics of scientific methodology, how math relates to science, what constitutes a theory, and even what attitudes to religion and generosity are appropriate as we inexorably approach the collapse of industrial civilization. Those wishing a comprehensive up to date framework for human behavior from the modern two systems view may consult my book ‘The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle’ 2nd ed (2019). Those interested in more of my writings may see ‘Talking Monkeys--Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet--Articles and Reviews 2006-2019 3rd ed (2019), The Logical Structure of Human Behavior (2019), and Suicidal Utopian Delusions in the 21st Century 4th ed (2019

The Rhetoric of Symmetry

References to the concept of symmetry have appeared in judicial opinions, advocacy efforts, and scholarly commentary throughout American legal history. But for every legal writer who invokes the concept as a logical or moral ideal, there is another who dismisses it as a formalistic distraction or an arid illusion. What is more, although legal writers virtually always use the term “symmetry” as if its meaning were self-evident, in fact they have used the same term to refer to a variety of distinct concepts, each with its own ambiguities

Logic in the Tractatus

I present a reconstruction of the logical system of the Tractatus, which differs from classical logic in two ways. It includes an account of Wittgenstein’s “form-series” device, which suffices to express some effectively generated countably infinite disjunctions. And its attendant notion of structure is relativized to the fixed underlying universe of what is named. There follow three results. First, the class of concepts definable in the system is closed under finitary induction. Second, if the universe of objects is countably infinite, then the property of being a tautology is \Pi^1_1-complete. But third, it is only granted the assumption of countability that the class of tautologies is \Sigma_1-definable in set theory. Wittgenstein famously urges that logical relationships must show themselves in the structure of signs. He also urges that the size of the universe cannot be prejudged. The results of this paper indicate that there is no single way in which logical relationships could be held to make themselves manifest in signs, which does not prejudge the number of objects

Certum atque Confessum: Lorenzo Valla on the Forensics of Certainty

At the center of Valla’s refashioning of dialectic as a rhetorical practice is a novel understanding of certainty taken from Quintilian’s handbook, an understanding of certainty rooted in what is agreed upon rather than what is objectively true. By separating certum from verum and by presenting dialectic as the practice of drawing out confessions rather than proving logical truths in his Dialecticae Disputationes, Valla recasts philosophical argumentation as a forensic project of crafting consensus-based certainties. In several other works, too, including his Elegantiae and marginal commentary on Quintilian’s Institutio itself, Valla consistently uses a set of vocabulary to link certainty with consensus, particularly the understanding of consensus at the heart of the ancient inventional strategy of status theory

Concerns with mutual constitution: a critical realist commentary

The case for “analytical dualism” as a means of approaching sociotechnical action is presented as an alternative to accounts which tend to conflate agency, structure, and technology. This is based on the work of Margaret Archer, whose work is in turn located in the traditions of critical realism. Her commitment to analytical dualism, which stresses both the importance of time in analysis and the emergent properties of structure, is argued to give a firmer purchase on the notion of context than the alternatives based on, for example, the work of Giddens and Latour