World Semantics Research Articles

The Problem of Counterfactuals in Substituted Judgement Decision‐Making

abstractThe standard by which we apply decision‐making for those unable to do so for themselves is an important practical ethical issue with substantial implications for the treatment and welfare of such individuals. The approach to proxy or surrogate decision‐making based upon substituted judgement is often seen as the ideal standard to aim for but suffers from a need to provide a clear account of how to determine the validity of the proxy's judgements. Proponents have responded to this demand by providing the truth‐conditions for the substituted judgement in terms of counterfactual reasoning using a possible worlds semantics. In this paper, I show how these underpinnings fail to support the substituted judgement approach as a reasonable standard for decision‐making. Firstly, I show how this counterfactual element has been poorly interpreted. I then explain how various accounts have failed to reflect problems and limitations associated with providing an interpretation of their truth‐conditions using counterfactuals. Finally, I argue that, even when we attend to the initial problems of providing a counterfactual analysis, it still deeply problematic as a means of determining the validity of substituted judgements for two main reasons. Firstly, making determinate judgements as to the truth‐value of these judgements will often not be possible and, secondly, there is a strong requirement when interpreting many counterfactual claims to charitably accede to their being true. I conclude that substituted judgements, as interpreted through counterfactual reasoning and possible worlds semantics, do not therefore provide an adequate standard for surrogate decision‐making.

Next-Generation Virtual Worlds: Architecture, Status, and Directions

It seems likely that the Web as we know it will undergo several paradigm shifts in the coming years: its content will expand from 2D documents to also accommodate 3D virtual worlds; with new technologies like RFID and smartphones, be able to link to a place or thing (in the real or virtual world) and associate more metadata annotations with things in the real and virtual worlds to create increasingly smart semantic worlds. But to realize these promises, the virtual world and ubiquitous computing communities will need architectures that are standard enough to become pervasive and flexible enough to expand beyond the applications we have today. This article describes some of the motivations and requirements for common core architectures for virtual worlds and introduces a track of articles that aim to change the way humans interact with the Web and their world.

Relativism and Monadic Truth

1. Overview: Simplicity, Possible Worlds Semantics and Relativism 2. Diagnostics for Shared Content: From 'Say' to 'Agree' 3. Operators, the Anaphoric 'That' and Temporally Neutral Propositions 4. Predicates of Personal Taste Bibliography

Rule induction for uncertain data

Data uncertainty are common in real-world applications and it can be caused by many factors such as imprecise measurements, network latency, outdated sources and sampling errors. When mining knowledge from these applications, data uncertainty need to be handled with caution. Otherwise, unreliable or even wrong mining results would be obtained. In this paper, we propose a rule induction algorithm, called uRule, to learn rules from uncertain data. The key problem in learning rules is to efficiently identify the optimal cut points from training data. For uncertain numerical data, we propose an optimization mechanism which merges adjacent bins that have equal classifying class distribution and prove its soundness. For the uncertain categorical data, we also propose a new method to select cut points based on possible world semantics. We then present the uRule algorithm in detail. Our experimental results show that the uRule algorithm can generate rules from uncertain numerical data with potentially higher accuracies, and the proposed optimization method is effective in the cut point selection for both certain and uncertain numerical data. Furthermore, uRule has quite stable performance when mining uncertain categorical data.

Double preference relations for generalised belief change

Many belief change formalisms employ plausibility orderings over the set of possible worlds to determine how the beliefs of an agent ought to be modified after the receipt of a new epistemic input. While most such possible world semantics rely on a single ordering, we investigate the use of an additional preference ordering—representing, for instance, the epistemic context the agent finds itself in—to guide the process of belief change. We show that the resultant formalism provides a unifying semantics for a wide variety of belief change operators. By varying the conditions placed on the second ordering, different families of known belief change operators can be captured, including AGM belief contraction and revision, Rott and Pagnucco's severe withdrawal, the systematic withdrawal of Meyer et al., as well as the linear liberation and σ-liberation operators of Booth et al. Our approach also identifies novel classes of belief change operators worthy of further investigation.

Ontological product modeling for collaborative design

This paper shows how to combine ontological and model-based techniques in languages that facilitate collaborative design exploration. The proposed approach uses ontology to capture alternative designs and incremental refinements that meet requirements and earlier design commitments. Model-based techniques are applied to develop more powerful, engineering-friendly languages for using ontology. It uses ontology’s open world semantics to support design collaboration with flexible and accurate design combination, refinement, and consistency checking. It also leads to more reliable interpretation of models across the product lifecycle due to more rigorous language semantics. An example language is described using these techniques.

Possible Worlds: Structure and Stuff

Timothy Williamson has defended the claim that any philosophically satisfying conception of modality that encompasses possible worlds semantics (PWS) commits us to the Barcan Formula. His argument depends on the assumption that the domain of what there is (the domain of the actual world) has to be identified with the domain D(@), where @ is the index or possible world that in PWS represents, or stands for, the actual world. I work out an interpretation of the relation between PWS and possible worlds terminology that makes it plausible to reject that assumption.

Dyadic deontic logic and semantic tableaux

The purpose of this paper is to develop a class of semantic tableau systems for some dyadic deontic logics. We will consider 16 different pure dyadic deontic tableau systems and 32 different alethic dyadic deontic tableau systems. Possible world semantics is used to interpret our formal languages. Some relationships between our systems and well known dyadic deontic logics in the literature are pointed out and soundness results are obtained for every tableau system. Completeness results are obtained for all 16 pure dyadic deontic systems and for 16 alethic dyadic deontic systems.

Causation and Conditionals in the Cognitive Science of Human Reasoning

This article traces the philosophical and psychological connections between causation and the conditional, if...then, across the two main paradigms used in conditional reasoning, the selection task and the conditional inference paradigm. It is argued that hypothesis testing in the selection task reflects the philosophical problems identified by Quine and Goodman for the material conditional interpretation of causal laws. Alternative formal theories to the material conditional only became available with the advent of possible worlds semantics (Lewis, 1973; Stalnaker, 1968). The relationship proposed by this semantics between counterfactual and indicative conditionals is outlined and it is concluded that moving away from the abstractions of possible worlds proposes a central role for prior knowledge in conditional inference. This conclusion is consistent with probabilistic approaches to conditional inference which provide measures of the strength of a dependency between the antecedent and the consequent of a conditional similar to those proposed in causal learning. Findings in conditional inference suggest that people are influenced not only by the strength of a dependency but also by the existence of the structural relationship, the broader causal framework in which a dependency is embedded, and the inhibitory and excitatory processes like those required to implement Causal Bayes nets or neural networks. That these findings may have a plausible explanation using the tools of current theories in causal learning suggests a potentially fruitful convergence of research in these two areas.

DESCRIPTION OF URBAN MODALITIES BY WALKTHROUGH EXPERIMENTS

The city is so complicated that we can hardly describe its totality. The purpose of this study is to clarify how we perceive cities, and what we recognize there. We introduce the concept of modality in order to grasp the total phenomena between human and environment as the global meaning of cities. We conduct walkthrough experiments in Kyoto City, and ask subjects of those experiments to write down what they feel as it is. The results are as follows.1) A theoretical model of urban modalities is constructed based on possible world semantics.2) Urban modalities can be described and visualized based on the data of walkthrough experiments.

Analyzing completeness of axiomatic functional systems for temporal × modal logics

AbstractIn previous works, we presented a modification of the usual possible world semantics by introducing an independent temporal structure in each world and using accessibility functions to represent the relation among them. Different properties ofthe accessibility functions (being injective, surjective, increasing, etc.) have been considered and axiomatic systems (called functional) which define these properties have been given. Only a few ofthese systems have been proved tobe complete. The aim ofthis paper is to make a progress in the study ofcompleteness for functional systems. For this end, we use indexes as names for temporal flows and give new proofs of completeness. Specifically, we focus our attention on the system which defines injectivity, because the system which defines this property without using indexes was proved to be incomplete in previous works. The only system considered which remains incomplete is the one which defines surjectivity, even ifwe consider a sequence ofnatural extensions ofthe previous one (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Functional systems in the context of temporal×modal logics with indexed flows

We consider logics which define different properties of functions – such as injectivity, surjectivity, monotonicity, etc. – in the context of temporal×modal logic. In this type of logics, the possible worlds semantics is modified by considering each world as a temporal flow and using accessibility functions to represent the connection among them. This approach is adequate to model interactions between processes with clocks that can be either synchronized or not. We study the definability and give indexed axiomatic systems for these properties.

COUNTERFACTUAL REASONING IN SURROGATE DECISION MAKING - ANOTHER LOOK

Incompetent patients need to have someone else make decisions on their behalf. According to the Substituted Judgment Standard the surrogate decision maker ought to make the decision that the patient would have made, had he or she been competent. Objections have been raised against this traditional construal of the standard on the grounds that it involves flawed counterfactual reasoning, and amendments have been suggested within the framework of possible worlds semantics. The paper shows that while this approach may circumvent the alleged problem, the way it has so far been elaborated reflects insufficient understanding of the moral underpinnings of the idea of substituted judgment. Proper recognition of these moral underpinnings has potentially far-reaching implications for our normative assumptions about accuracy and objectivity in surrogate decision making.

An epistemic model of an agent who does not reflect on reasoning processes

This paper introduces an epistemic model of a boundedly rational agent under the two assumptions that (i) the agent’s reasoning process is in accordance with the model but (ii) the agent does not reflect on these reasoning processes. For such a concept of bounded rationality a semantic interpretation by the possible world semantics of the Kripke (1963) type is no longer available because the definition of knowledge in these possible world semantics implies that the agent knows all valid statements of the model. The key to my alternative semantic approach is the extension of the method of truth tables, first introduced for the propositional logic by Wittgenstein (1922), to an epistemic logic so that I can determine the truth value of epistemic statements for all relevant truth conditions. In my syntactic approach I define an epistemic logic–consisting of the classical calculus of propositional logic plus two knowledge axioms–that does not include the inference rule of necessitation, which claims that an agent knows all theorems of the logic. As my main formal result I derive a determination theorem linking my semantic with my syntactic approach. The difference between my approach and existing knowledge models is illustrated in a game-theoretic application concerning the epistemic justification of iterative solution concepts.

Counterfactuals and semantic tableaux

The purpose of this paper is to develop a class of semantic tableau systems for some counterfactual logics. All in all I will discuss 1024 systems. Possible world semantics is used to interpret our formal languages. Soundness results are obtained for every tableau system and completeness results for a large subclass of these.

C. I. Lewis on Possible Worlds

This article opposes a view widely accepted in studies concerning the history of modal logic, according to which (i) the approach of C. I. Lewis towards constructing modern modal logic was purely syntactical (i.e. limited to the construction of axiomatic systems S1–S5 of propositional modal logic), and (ii) the notion of a possible world was incorporated into modern logic and philosophy mainly by authors such as Rudolf Carnap and Saul Kripke. The article presents Lewis' definition of a possible world, and his formulation of the truth-conditions of statements containing strict implication as their main connective in terms of possible worlds. The main question of the article is whether it is possible to consider Lewis' work in this area as an early stage of the development of possible world semantics, and if so, in what sense? The article concludes by answering affirmatively, due to soundness and completeness proofs with respect to S5 using Lewis' semantics.

The Philosophy of Literature * By PETER LAMARQUE

As a recent distinguished editor of British Journal of Aesthetics and a major contributor in his own right to recent debates on aesthetics and the philosophy of art – not least in the particular field with which this particular volume is concerned – Peter Lamarque is particularly well placed to author this survey of past and contemporary work on the philosophy of literature. Moreover, as those already familiar with Professor Lamarque's work will no doubt expect, this volume offers remarkably clear and extensive coverage of a wide and complex philosophical field in its relatively short space of under 300 pages. Following a short preface, the work is divided into seven chapters. The first, entitled ‘Art’, generally explores the relationship between philosophy, literary theory, art and literature and offers useful critical discussions of different concepts of aesthetics (as experience, ‘qualities’ and pleasure). The second looks more closely at the question of what it means to regard some texts as ‘literature’ and discusses a range of (essentialist and anti-essentialist) attempts to explain the special literary status of some texts. The third chapter examines the vexed question of the role and/or authority of the author in determining the meaning of literary works and offers some balanced and useful assessment of more extreme attempts of post-structuralists such as Barthes and Foucault to downplay this role. Chapter 4, entitled (a little vaguely) ‘Practice’, focuses more centrally on issues of literary meaning and interpretation, with some interesting exploration of the problems of taking discovery of meaning (at any rate, as this notion is often philosophically construed) to be the main focus of literary reading or criticism. Chapter 5 starts to open up difficult questions about the relationship of works of literature to reality and truth via exploration of the concept of fiction and attention to various attempts (from Meinong and Russell to more recent possible worlds semantics) to make sense of fictional or non-existent entities. Chapter 6 focuses more fully on important question of truth in literature and on the extent to or sense in which fictional or other works of literature might be regarded as sources of knowledge. Finally, Chapter 7 discusses different accounts of the value of literature, distinguishing between different conceptions of value as such, as well as offering a very useful (if somewhat sceptical) perspective on the moral significance of literature.

Conditionals and Actuality

It is known that indicative and subjunctive conditionals interact differently with a rigidifying “actually” operator. The paper studies this difference in an abstract setting. It does not assume the framework of possible world semantics, characterizing “actually” instead by the type of logically valid formulas to which it gives rise. It is proved that in a language with such features all sentential contexts that are congruential (in the sense that they preserve logical equivalence) are extensional (in the sense that they preserve material equivalence). For a subjunctive conditional, the natural conclusion to draw is that it is non-congruential. It is much harder to defend the claim that an indicative conditional is non-congruential. The pressure to treat the indicative conditional as truth-functional is correspondingly greater. The implications of these results for attempts to interpret the indicative conditional as an epistemic or doxastic operator are assessed.

Lisää käyttöä mahdollisille maailmoille

More Uses for Possible Worlds In the context of literary studies, the concepts of possible worlds semantics have thus far been applied mostly in the analysis of works which thematize ontological issues and the worlds of fiction. The article considers ways in which literary narratology could gain from utilizing more systematically the concepts developed in the context of possible worlds semantics. The principal argument of the article is that narratology informed by possible worlds semantics – in other words, possible world poetics – should be considered as partaking in the project of descriptive poetics. Possible world poetics insists both on the indispensability of the semantic and referential aspects of literature and on the textual origins of the projected worlds and meanings. As a result, it arguably provides a fairly refined conceptual apparatus for the description of narrative fiction. The analytic part of the article demonstrates the point by incorporating two essential concepts of possible worlds poetics into text-analytic practice vis-a-vis the novel Rinnakkain (‘Side by Side’, 2004) by Reko Lundan. Taking its cue from Lubomir Doležel, the discussion concentrates first on the intensional functions of the novel, the intensional function of authentication in particular. The second notion under consideration is the diversification of possible worlds as the source of tellability, a hypothesis formulated by Marie-Laure Ryan. The article closes with a consideration of the interpretative ramifications of possible world poetics.

Web service composition: a semantic web and automated planning technique application

This article proposes applying semantic web and artificial intelligence planning techniques to a web services composition model dealing with problems of ambiguity in web service description and handling incomplete web information. The model uses an OWL-S services and implements a planning technique which handles open world semantics in its reasoning process to resolve these problems. This resulted in a web services composition system incorporating a module for interpreting OWL-S services and converting them into a planning problem in PDDL (a planning module handling incomplete information) and an execution service module concurrently interacting with the planner for executing each composition plan service.