Skip to main content

The plurality of logics in UNILOG

Unilog is taking place in Rio in early April. We (Alexandre Costa-Leite and me) hope to make an official début there of our much rehearsed galaxy theory. The abstract of our presentation there gives an idea of what we are after in the paper (currently submitted to Logica Uniersalis):

The availability of multiple logics, although not a novelty, carries on provoking different kinds of puzzlement. From the point of view of those endeavoring to describe and understand parts of the world, it is a pressing issue to understand how different logics coexist – and eventually how to choose between them. For metaphysicians, who often deal in necessity and make frequent use of modal reasoning, the appeal to a logic is also the appeal to a standard to decide what is possible – typically in terms of which worlds are possible (see D. Lewis’ On the plurality of worlds). The use of a single, fixed logic as a standard of possibility is clearly unsatisfactory as it biases all results. Clearly, what is impossible in classical logic is not necessarily so in paraconsistent or intuitionistic logics. Up till now, the use of classical logic as if it were there only logic available was defended on the basis of its entrenchment: in the absence of any reason to pick any other logic, classical logic is best retained once it is deemed sufficiently useful and intuitive in the past. Such a response, nevertheless, has been challenged by the development of tools for a universal logic.

Universal logic engages with multiple logics simultaneously either by comparing them or by combining them. It made it possible to look at the plurality of logics not in order to choose one among them but rather to study relations between them. By considering the space of all logics, universal logic provides a general framework where features and capacities of a logic can be made evident. We have recently sketched a tool for universal logic called galaxy theory. Based on some developments in Kripke’s semantics for modal logic, galaxy theory defines a logic (or rather, a relation of consequence) as a class of possible worlds. Such a class, called galaxy, is itself an element in a topology of galaxies. Typically, modal elements in a logic add to each corresponding galaxy some relations of access, but this can be taken not to affect the underlying galaxy. The emerging image is one where the plurality of logics can be studied as the plurality of galaxies.

In this work we present the framework of galaxies and apply it to the debate about realism concerning different logics – and related issues revolving around dialetheism. We consider galaxy theory together with some concepts developed by Kit Fine (mainly in papers collected in “Modality and Tense”), such as the notion of a inconsistent über-reality that brings together elements in a plurality. We then propose a realism about the different logics that is, at the same time, combined to a form of dialetheism. Galaxy theory paves the way to investigate such issues because it takes each galaxy as a point in a topology. A side aim of this work, nevertheless important, is to show how fruitful the framework of galaxies can be.

Comments

Popular posts from this blog

Hunky, Gunky and Junky - all Funky Metaphysics

Been reading Bohn's recent papers on the possibility of junky worlds (and therefore of hunky worlds as hunky worlds are those that are gunky and junky - quite funky, as I said in the other post). He cites Whitehead (process philosophy tends to go hunky) but also Leibniz in his company - he wouldn't take up gunk as he believed in monads but would accept junky worlds (where everything that exists is a part of something). Bohn quotes Leibniz in On Nature Itself «For, although there are atoms of substance, namely monads, which lack parts, there are no atoms of bulk, that is, atoms of the least possible extension, nor are there any ultimate elements, since a continuum cannot be composed out of points. In just the same way, there is nothing greatest in bulk nor infinite in extension, even if there is always something bigger than anything else, though there is a being greatest in the intensity of its perfection, that is, a being infinite in power.» And New Essays: ... for there is nev...

Memory assemblages

My talk here at Burque last winter I want to start by thanking you all and acknowledging the department of philosophy, the University of New Mexico and this land, as a visitor coming from the south of the border and from the land of many Macroje peoples who themselves live in a way that is constantly informed by memory, immortality and their ancestors, I strive to learn more about the Tiwas, the Sandia peoples and other indigenous communities of the area. I keep finding myself trying to find their marks around – and they seem quite well hidden. For reasons to do with this very talk, I welcome the gesture of directing our thoughts to the land where we are; both as an indication of our situated character and as an archive of the past which carries a proliferation of promises for the future. In this talk, I will try to elaborate and recommend the idea of memory assemblage, a central notion in my current project around specters and addition. I begin by saying that I ...

The underground of concepts: my talk at the Marxism and the Pittsburgh School Conference

In few minutes I'll be presenting this talk in the Marxism and the Pittsburgh School conference in the UCL. I can still change the text but this is how it looks like now. The underground of concepts: McDowell on the productivity of Anschauungen Hilan Bensusan 1. Jean-François Lyotard diagnosed the idea that concepts do the productive work of thinking as a deception. It is not through a dynamics of concepts that conclusions are reached and it is not with the decisive intervention of them that conflicts between alternatives resolved. Lyotard compares the pretense that concepts think with the mystification that capital works. He argues that “what works is not the concept, […] the concept is [like] capital which pretends to work, but which [only] determines the conditions of labour, delimits the outsides and insides, the authorized and the prohibited” (Lyotard, Libidinal Economy, p. 13). This diagnosis, frequently lost in the middle of an ampler argumentation around t...