Possible world semantics definition of possible world. Indeed, this is the only kind of application we are considering in this chapter. The semantics of bi the logic of bunched implications, bi, is a substructural system which freely combines an. Possible worlds semantics and fiction springerlink. Despite previous work indicating that we have formalized modal intuitions into a complete and consistent logical system, we have not.
Semantics, possible worlds routledge encyclopedia of philosophy. Thus, a novel interpretation of applied possible worlds semantics is offered on which we may lay claim to whatever benefits such a theory offers while avoiding realism about other possible worlds. A statement in modal logic that is possible is said to be true in at least one possible world. This chapter discusses the philosophical theories and presuppositions of applying possible worlds semantics in order to draw conclusions about matters involving what are called conceptual or broadly logical possibilities and necessities. The third will examine one rather sophisticated attempt to accommodate adams s thesis within a modified possible worlds framework, one which treats conditionals as random variables taking semantic. Incompleteness theory of euclidean possibleworlds semantics. Ohearn hongseok yang november 29, 2002 abstract the logic of bunched implications, bi, is a substructural system which freely combines an additive intuitionistic and a multiplicative linear implication via bunches contexts with two combining oper. But in all possible worlds, that entity exists at one time or another. Jack copeland, journaljournal of philosophical logic, year2002, volume31, pages997 b. Possible worlds cornell university according to leibniz, the universethe actual worldis one of an infinite number of possible worlds existing in the mind of god.
The meaning of an expression, on this view, comprises not just the expressions reference in the actual world, but also what the expression would have referred to, had the actual world been di erent. In the paper we will study the notions of possibleworlds semantics, fiction, and creativity. Thereby, the contention that applied possibleworlds semantics gives us reason to be realists about possible worlds is further undermined. Since dunns semantics shifts the focus of modal semantics from possible worlds to propositions, section 4 replaces the definition of proposition as a set of possible worlds with a more finegrained definition as an equivalence class of sentences. I have one more question about possible world semantics in general. Though possible worlds semantics has long been established as the dominant research tradition in philosophical logic and its applications, its various theories. Possible worlds semantics pws is a family of ideas and methods that have been used to analyse concepts of philosophical interest. For instance, in possible worlds semantics, the proposition matt has a dog would be thought of as the set of worlds in which matt has a dog. Girle 2003 and girle 2000 are introductory textbooks on formal possible worlds semantics in modal logic. Possible worlds semantics have been widely applied both in philosophy and in other fields such as linguistic semantics and pragmatics, theoretical computer science, and game theory. More basically, you can use possible worlds to cash out the idea of an inferences being valid.
I distinguish haecceitism and antihaecceitism from other doctrines which sometimes go under those names. Possible worlds stanford encyclopedia of philosophy. This paper contains an argument to the effect that possible worlds semantics renders semantic knowledge impossible, no matter what ontological interpretation is given to possible worlds. The possible worlds model for logics of knowledge and belief was originally proposed by hintikka hintikka, 1962, and is now most commonly formulated in a normal modal logic using the techniques developed by kripke kripke, 1963. Proponents includeborghini and williams2008,jacobs2010, andcontessa2010. Claims, or what philosophers like to call propositions, can be thought of as sets of possible worlds. Multidimensional possibleworld semantics for conditionals. Incompleteness theory of euclidean possibleworlds semantics and resolution of the surprise quiz paradox i abstract our best attempt at formalizing modal intuitions in a logical system fails. The genesis of possible worlds semantics request pdf.
Possible worlds semantics for pictures dorit abusch december 2015 1. A similar analysis for predicate bi 2, building on the present analysis, is treated in 3. God created the universe by actualizing one of these possible worlds the best one. Possible worlds semantics philosophy 431 february 5, 20 i. This logic plays a fundamental role in providing an arithmetic semantics for rstorder intuitionistic logic, as was shown. This logic plays a fundamental role in providing an arithmetic semantics for. The genesis of possible worlds semantics semantic scholar. A problem for kratzers semantics zsofia zvolenszky new york university 1. Readers familiar with basic possible world semantics can skip to 2 with no.
The concluding section discusses new representations in linguistics and new methods of. It is possible to distinguish homophones same sound and homographs same. On the methodology of possible worlds semantics, i project euclid. The intention is to show how the notion of possible worlds semantics allows us to generate a fresh interpretation of the notions of fiction and creativity. The ontology of impossible worlds vander laan, david a. Introduction in the philosophy of language and linguistic semantics, there is an approach to semantics and pragmatics that proceeds by assigning semantic values to sentences, and then reasoning about pragmatics in terms of these semantic values. Possible worlds semantics for pictures dorit abusch april 28, 2019 1. Pdf safety, the preface paradox and possible worlds. Suppose there is some entity that exists in all possible worlds, but in some of those possible worlds, it doesnt always exist. It is often contrasted with the way things actually are.
Intensional approaches to semantics model the meaning of a language or a fragment using more than extensionsthey acknowledge that with. Specifically, in possible world semantics, the modal operators are interpreted as. This chapter discusses the general contrast between modal realism and actualism and questions about the kind of explanation that possible worlds provide for modal. In the philosophy of language and linguistic semantics, there is an. A semantics for modal logic was first introduced in the late1950s work of saul kripke and his colleagues. This is not the place to discuss the metaphysics of possible worlds in any depth. Pws was originally focused on the important concepts of necessity and possibility. This chapter explores the dominant semantics for modal expressions in formal semantics, including kratzers developments for contextsensitive natural language semantics. In addition to the usual sentence operators of classical logic such as and. One world says how things really are, the other worlds say how things could be. Possible world, conception of a total way the universe might have been.
Possibleworlds talk obscures the debate about haecceitism, rather than clarifying it. Propositional quantification in the topological semantics for s4 kremer, philip, notre dame journal of formal logic, 1997. Since the pioneering work by kripke and montague, the term possible world has appeared in most theories of formal semantics for modal logics, natural languages, and knowledgebased systems. Possible worlds in logic philosophy stack exchange. God created the universe by actualizing one of these possible worldsthe best one. This era perhaps began with the work of peirce, who advocated an analysis of the conditional in terms of quanti. The essential contention made is that possible worlds semantic. Rather, it is the semantic theory itself more exactly, the logic in which the theory is expressed that is extensional. Final thoughts on truthconditional semantics 10 minutes.
To set the stage for the possible worlds semantics, consider the following presentation of freges puzzle. Providing a possible worlds semantics for a logic involves choosing a class of possible worlds models, and setting up a truth definition connecting formulas of the logic with statements about these models. Possible worlds have also been used to give a semantics for counterfactual conditionals, though this is more controversial. Pdf grounding possible worlds semantics in experiential. The semantics of bi the logic of bunched implications, bi, is a substructural system which freely combines an additive intuitionistic and a. Instead, we will just start working with them and see what they can do for us. Leibniz used the concept of a possible world in his proposed solution to the theological problem of the existence of evil, arguing that an. It explains how an account developed in terms of the technical devices of ordering sources and background conditions can be used to generate a semantics for ought that makes reasonable predictions. The purpose of this paper is to explore in some detail the possible worlds semantics of propositional bi sketched in 1. Possible worlds semantics for ought oxford scholarship. Thus, a novel interpretation of applied possibleworlds semantics is offered on which we may lay claim to whatever benefits such a theory offers while avoiding realism about other possible worlds. Hintikkas insight was to see that an agents beliefs could be characterized as a set of possible worlds, in the. Modal sentences like 1 and 2 concern what is necessary or possible and. Parallel worlds works, but quite complicated and not very intuitive.
In some of those worlds, it comes into being from a state of nonexistence. Pdf on jan 1, 1997, john perry and others published u039 semantics, possibleworlds find, read and cite all the research you. Possible world semantics for first order lp melvin fitting april 7, 2012 abstract in the tech report 3 an elegant formulation of the rstorder logic of proofs was given, folp. Thereby, the contention that applied possible worlds semantics gives us reason to be realists about possible worlds is further undermined. Although possible world has been part of the philosophical lexicon at least since leibniz, the notion became firmly entrenched in contemporary philosophy with the development of possible world semantics for the languages of propositional and firstorder modal logic. Since the pioneering work by kripke and montague, the term possible world has appeared in most. The language is interpreted by assigning intensions to the expressions, where an intension is a function from possible worlds to extensions of the appropriate type individuals for. Also available online in html, pdf, and epub formats in a. Possible worlds semantics philosophy 431 february 5, 20. Semantics is the part of linguistics that studies meaning in language. More precisely, the semantic contents of the lsentences can be specified by a mapping v from pairs of sentences and possible worlds to the set of permissible semantic values. If the antihumean is to do without such tools as possible worlds, she will do well to develop a modal semantics of 4. Semantics, possible worlds routledge encyclopedia of. Every purely logical truth is necessary in this sense, but the set of conceptually necessary truths includes much more.
Possible worlds semantics university of notre dame. Nov 03, 2011 possible worlds semantics is based around this second idea. This is a good point to make a comment which relates to the place of this chapter. Leibniz used the concept of a possible world in his proposed solution to the theological problem of the existence of evil, arguing that an allperfect god would actualize the best of all possible worlds. Possible world semantics synonyms, possible world semantics pronunciation, possible world semantics translation, english dictionary definition of possible world semantics. Possible worlds semantics is based around this second idea. If we use extension as a label for the reference of an expression so that the extensions of names are objects, and the extensions of simple predicates are functions from objects to truthvalues we can introduce intension as a label for an expressions reference across possible worlds. Multidimensional possibleworld semantics for conditionals richard bradley. This is the guiding idea of possible worlds semantics.
Hintikkas insight was to see that an agents beliefs could be characterized as a set of possible worlds, in the following way. This paper reassesses lewiss theory and draws attention to some novel problems for his account. The canonical version of possible worlds semantics for story prefixes is due to david lewis. Meaning of a word is the collection of its references in all worlds. It can be found in contemporary epistemology and ethics, and has even found its way into linguistics and decision theory. Incompleteness theory of euclidean possible worlds semantics and resolution of the surprise quiz paradox i abstract our best attempt at formalizing modal intuitions in a logical system fails. Is a possibleworlds semantics of modality possible. Multidimensional possibleworld semantics for conditionals lse. To do this, we have to consider the philosophy of logic. Probabilistic logic networks pln, a comprehensive framework for uncertain inference currently in use in the opencog and novamente cognition engine agi software architectures, has previously been described in terms of the experiential semantics of. As noted, possible world semantics does not make modal logic itself extensional. Possible worlds the concept of possible worlds henceforth pw, loosely inspired by leibniz philosophy, was developed in the second half of the 20th century by philosophers of the analytic school kripke, lewis, hintikka 1989, plantinga 1976, rescher as a means to solve problems in formal semantics.