The purpose of this book is to develop a terminological structure in which private perceptions can be discussed publicly without bringing into existence the usual unnecessary philosophical problems of confused usage of language. chisholm displays an appraisive, quasi-ethical use of language, whereby he claims that a thing has some particular sensible property is to have adequate evidence that it actually does have that property. (staff).

This book is the first in the field of paraconsistency to offer a comprehensive overview of the subject, including connections to other logics and applications in information processing, linguistics, reasoning and argumentation, and philosophy of science. It is recommended reading for anyone interested in the question of reasoning and argumentation in the presence of contradictions, in semantics, in the paradoxes of set theory and in the puzzling properties of negation in logic programming. Paraconsistent logic comprises a major logical theory and (...) offers the broadest possible perspective on the debate of negation in logic and philosophy. It is a powerful tool for reasoning under contradictoriness as it investigates logic systems in which contradictory information does not lead to arbitrary conclusions. Reasoning under contradictions constitutes one of most important and creative achievements in contemporary logic, with deep roots in philosophical questions involving negation and consistency This book offers an invaluable introduction to a topic of central importance in logic and philosophy. It discusses the history of paraconsistent logic; language, negation, contradiction, consistency and inconsistency; logics of formal inconsistency and the main paraconsistent propositional systems; many-valued companions, possible-translations semantics and non-deterministic semantics; paraconsistent modal logics; first-order paraconsistent logics; applications to information processing, databases and quantum computation; and applications to deontic paradoxes, connections to Eastern thought and to dialogical reasoning. (shrink)

‘It is of the very nature of consciousness to be intentional’ said Jean-Paul Sartre, ‘and a consciousness that ceases to be a consciousness of something would ipso facto cease to exist’.1 Sartre here endorses the central doctrine of Husserl’s phenomenology, itself inspired by a famous idea of Brentano’s: that intentionality, the mind’s ‘direction upon its objects’, is what is distinctive of mental phenomena. Brentano’s originality does not lie in pointing out the existence of intentionality, or in inventing the terminology, which (...) derives from scholastic discussions of concepts or intentiones.2 Rather, his originality consists in his claim that the concept of intentionality marks out the subject matter of psychology: the mental. His view was that intentionality ‘is characteristic exclusively of mental phenomena. No physical phenomenon manifests anything like it’.3 This is Brentano’s thesis that intentionality is the mark of the mental. Despite the centrality of the concept of intentionality in contemporary philosophy of mind, and despite the customary homage paid to Brentano as the one who revived the terminology and placed the concept at the centre of philosophy, Brentano’s thesis is widely rejected by contemporary philosophers of mind. What is more, its rejection is not something which is thought to require substantial philosophical argument. Rather, the falsity of the thesis is taken as a starting-point in many contemporary discussions of intentionality, something so obvious that it only needs to be stated to be recognised as true. Consider, for instance, these remarks from the opening pages of Searle’s Intentionality: Some, not all, mental states and events have Intentionality. Beliefs, fears, hopes and desires are Intentional; but there are forms of nervousness, elation and undirected anxiety that are not Intentional.... My beliefs and desires must always be about something. But my nervousness and undirected anxiety need not in that way be about anything.4 Searle takes this as obvious, so obvious that it is not in need of further argument or elucidation. (shrink)

A logic is called 'paraconsistent' if it rejects the rule called 'ex contradictione quodlibet', according to which any conclusion follows from inconsistent premises. While logicians have proposed many technically developed paraconsistent logical systems and contemporary philosophers like Graham Priest have advanced the view that some contradictions can be true, and advocated a paraconsistent logic to deal with them, until recent times these systems have been little understood by philosophers. This book presents a comprehensive overview on paraconsistent logical systems to change (...) this situation. The book includes almost every major author currently working in the field. The papers are on the cutting edge of the literature some of which discuss current debates and others present important new ideas. The editors have avoided papers about technical details of paraconsistent logic, but instead concentrated upon works that discuss more 'big picture' ideas. Different treatments of paradoxes takes centre stage in many of the papers, but also there are several papers on how to interpret paraconistent logic and some on how it can be applied to philosophy of mathematics, the philosophy of language, and metaphysics. (shrink)

In this paper we offer a new argument for the existence of God. We contend that the laws of logic are metaphysically dependent on the existence of God, understood as a necessarily existent, personal, spiritual being; thus anyone who grants that there are laws of logic should also accept that there is a God. We argue that if our most natural intuitions about them are correct, and if they are to play the role in our intellectual activities that we take (...) them to play, then the laws of logic are best construed as necessarily existent thoughts -- more specifically, as divine thoughts about divine thoughts. We conclude by highlighting some implications for both theistic arguments and antitheistic arguments. (shrink)

I provide an interpretation of Wittgenstein's much criticized remarks on Gödel's First Incompleteness Theorem in the light of paraconsistent arithmetics: in taking Gödel's proof as a paradoxical derivation, Wittgenstein was right, given his deliberate rejection of the standard distinction between theory and metatheory. The reasoning behind the proof of the truth of the Gödel sentence is then performed within the formal system itself, which turns out to be inconsistent. I show that the models of paraconsistent arithmetics (obtained via the Meyer-Mortensen (...) collapsing filter on the standard model) match with many intuitions underlying Wittgensteins philosophy of mathematics, such as its strict finitism and the insistence on the decidability of any meaningful mathematical question. (shrink)