A logic is said to be paraconsistent if it does not allow everything to follow from contradictory premises. There are several approaches to paraconsistency. This paper is concerned with several philosophical positions on paraconsistency. In particular, it concerns three ‘schools’ of paraconsistency: Australian, Belgian and Brazilian. The Belgian and Brazilian schools have raised some objections to the dialetheism of the Australian school. I argue that the Australian school of paraconsistency need not be closed down on the basis of the Belgian (...) and Brazilian schools’ objections. In the appendix of the paper, I also argue that the Brazilian school’s view of logic is not coherent. (shrink)

In this paper, I take up three tasks in turn. The first is to set out what Routley thought we should demand of an all-purpose universal logic, and some of his reasons for those demands. The second is to sketch Routley's own response to those demands. The third is to explore how else we could satisfy some of the theoretical demands Routley identified, if we are not to follow him in endorsing Routleyan Ultralogic as a foundational logic. As part of (...) this third project, I articulate what seems to me a preferable way of going to respond to the challenges Routley correctly identifies: and while I doubt what I will have to say would have convinced Routley himself, I will try to show that the approach I prefer has several advantages over Routley's. (shrink)

Even though Richard Routley is known as a proponent of so-callednuclear Meinongianism (in his terminology, noneism), the details of hisview in Exploring Meinong’s Jungle and Beyond (1980) have not attractedmuch attention. In this paper, I critically examine two notablebut less known features of Meinongianism in Routley (1980) which particularlyconcern a core claim of nuclear Meinongianism that so-calledCharacterization Principle (CP) is applicable to nuclear properties(in his terminology, characterizing properties) but not to extranuclearproperties (in his terminology, noncharacterizing properties): The firstone is his (...) ‘double determination’ argument for restricting the class ofproperties to which CP is applicable; and the second is his expansionof the class of nuclear properties in terms of the supposition operator s.Firstly, I will show that the double determination argument fails, since,for some extranuclear properties, the argument fails to justify that CPis not applicable to them, and, moreover, the argument unintendedlyshows that CP is not applicable to some nuclear properties. Secondly,based on the idea that the supposition operator, combined with anyproperty f, forms the intensional property of being assumed to havef, I will give a formal treatment of the supposition operator withinthe framework of world semantics. We will see that this interpretationgoes beyond Routley’s original nuclear Meinongianism and assimilateshis view with modal Meinongianism proposed by Priest (2005, 2016). (shrink)

Abstract:The paper is devoted to the presentation of Chwistek’s philosophical ideas concerning logic and mathematics. The main feature of his philosophy was nominalism, which found full expression in his philosophy of mathematics. He claimed that the object of the deductive sciences, hence in particular of mathematics, is the expression being constructed in them according to accepted rules of construction. He treated geometry, arithmetic, mathematical analysis and other mathematical theories as experimental disciplines, and obtained in this way a nominalistic interpretation of (...) them. The fate of Chwistek’s philosophical conceptions was similar to the fate of his logical conceptions. The system of rational meta-mathematics was not developed by him in detail. He worked on his own ideas without any collaboration with other logicians, mathematicians or philosophers. His investigations were not in the mainstream of the development of logic and philosophy of mathematics. (shrink)

Richard Sylvan (né Routley) was one of Australasia's most prolific and systematic philosophers. Though known for his innovative work in logic and metaphysics, the astonishing breadth of his philosophical endeavours included almost all reaches of philosophy. Taking the view that very basic assumptions of mainstream philosophy were fundamentally mistaken, he sought radical change across a wide range of theories. However, his view of the centrality of logic and recognition of the possibilities opened up by logical innovation in the fundamental areas (...) of metaphysics resulted in his working primarily in these two, closely connected fields. It is this work in logic and metaphysics that is the main focus of what follows. (shrink)

Introduction to the Routley/Sylvan Issue.

This essay in the comparative metaphysic of nothingness begins by pondering why Leibniz thought of the converse question as the preeminent one. In Eastern philosophical thought, like the numeral 'zero' (śūnya) that Indian mathematicians first discovered, nothingness as non-being looms large and serves as the first quiver on the imponderables they seem to have encountered (e.g., 'In the beginning was neither non-being nor being: what was there, bottomless deep?' RgVeda X.129). The concept of non-being and its permutations of nothing, negation, (...) nullity, etc., receive more sophisticated treatment in the works of grammarians, ritual hermeneuticians, logicians, and their dialectical adversaries variously across Jaina and Buddhist schools. The present analysis follows the function of negation/the negative copula, nãn, and dialetheia in grammar and logic, then moves onto ontologies of non-existence and extinction and further suggestive tropes that tend to arrest rather than affirm the inexorable being-there of something. After a discussion of interests in being (existence), non-being and nothingness in contemporary metaphysics, the article examines Heidegger’s extensive treatment of nothingness in his 1929 inaugural Freiburg lecture, 'Was ist Metaphysik?', published later as 'What is Metaphysics?' The essay however distances itself from any pretensions toward a doctrine of Metaphysical Nihilism. (shrink)

This essay in the comparative metaphysic of nothingness begins by pondering why Leibniz thought of the converse question as the preeminent one. In Eastern philosophical thought, like the numeral 'zero' (śūnya) that Indian mathematicians first discovered, nothingness as non-being looms large and serves as the first quiver on the imponderables they seem to have encountered (e.g., 'In the beginning was neither non-being nor being: what was there, bottomless deep?' RgVeda X.129). The concept of non-being and its permutations of nothing, negation, (...) nullity, etc., receive more sophisticated treatment in the works of grammarians, ritual hermeneuticians, logicians, and their dialectical adversaries variously across Jaina and Buddhist schools. The present analysis follows the function of negation/the negative copula, nãn, and dialetheia in grammar and logic, then moves onto ontologies of non-existence and extinction and further suggestive tropes that tend to arrest rather than affirm the inexorable being-there of something. After a discussion of interests in being (existence), non-being and nothingness in contemporary metaphysics, the article examines Heidegger’s extensive treatment of nothingness in his 1929 inaugural Freiburg lecture, 'Was ist Metaphysik?', published later as 'What is Metaphysics?' The essay however distances itself from any pretensions toward a doctrine of Metaphysical Nihilism. (shrink)

The question of ontological foundation has undergone a noteworthy revival in recent years: metaphysicians today quarrel about how exactly to understand the asymmetrical and hyperintensional relationship of grounding. One of the reasons for this revival is that the old quantificationalist meta-ontology inherited from Quine has been effectively criticised by leading philosophers favourable to a meta-ontology, the aim of which is to come to know “which facts/items ground (constitute the base of) which other facts/items”, thus to examine the relation of ontological (...) dependence between beings (e.g. chemical properties depend on physical properties, the economic situation on the behaviour of individuals etc.), i.e. to explore the hierarchical structure of reality. I shall not discuss here the relationship of grounding in itself, but make some historical-formal remarks on the properties of the ultimate ontological foundational item itself and its aporetic nature. To do so I explore various more or less exotic philosophical ecosystems in the following order: Heidegger (Seyn), Plato (ἕν), Wáng Bi (道, dào). On the way I shall propose a new interpretation both of certain hypotheses in the Parmenides and of the nature of the opposition between Wáng Bì and Guō Xiàng in regard to the logical grammar of the expression “nothing (無, wú)” (transl. J. Dudley). (shrink)