Modelling Deep Indeterminacy

This paper constructs a model of metaphysical indeterminacy that can accommodate a kind of ‘deep’ worldly indeterminacy that arguably arises in quantum mechanics via the Kochen-Specker theorem, and that is incompatible with prominent theories of metaphysical indeterminacy such as that in Barnes and Williams (2011). We construct a variant of Barnes and Williams's theory that avoids this problem. Our version builds on situation semantics and uses incomplete, local situations rather than possible worlds to build a model. We evaluate the resulting theory and contrast it with similar alternatives, concluding that our model successfully captures deep indeterminacy

A probabilistic database extension

Data exchange between embedded systems and other small or large computing devices increases. Since data in different data sources may refer to the same real world objects, data cannot simply be merged. Furthermore, in many situations, conflicts in data about the same real world objects need to be resolved without interference from a user. In this report, we report on an attempt to make a RDBMS probabilistic, i.e., data in a relation represents all possible views on the real world, in order to achieve unattended data integration. We define a probabilistic relational data model and review standard SQL query primitives in the light of probabilistic data. It appears that thinking in terms of `possible worlds¿ is powerful in determining the proper semantics of these query primitives

Where Sensitivity Don't Work

Robert Nozick (1981, 172) offers the following analysis of knowledge (where S stands for subject and p for proposition): D1 S knows that p =df (1) S believes p, (2) p is true, (3) if p weren’t true, S wouldn’t believe that p (variation condition), and (4) If p were true, S would believe it (adherence condition). Jointly, Nozick refers to conditions 3 and 4 as the sensitivity condition: for they require that the belief be sensitive to the truth-value of the proposition—such that if the proposition were false, the subject would not have believed it, and if the proposition remains true in a slightly different situation, the subject would have still believed it. In other words, they ask us to consider the status of the belief in close possible situations (those that obtain in close possible worlds); specifically, in situations that would obtain if the proposition is false, and in those in which it remains true. Condition 3 specifies how belief should vary with the truth of what is believed, while condition 4 specifies how belief shouldn’t vary when the truth of the belief does not vary. I will discuss some notable problem cases for Nozick’s analysis and then look at why the sensitivity condition he proposes fails in these cases

Adaptive Dynamics of Realistic Small-World Networks

Continuing in the steps of Jon Kleinberg's and others celebrated work on decentralized search in small-world networks, we conduct an experimental analysis of a dynamic algorithm that produces small-world networks. We find that the algorithm adapts robustly to a wide variety of situations in realistic geographic networks with synthetic test data and with real world data, even when vertices are uneven and non-homogeneously distributed. We investigate the same algorithm in the case where some vertices are more popular destinations for searches than others, for example obeying power-laws. We find that the algorithm adapts and adjusts the networks according to the distributions, leading to improved performance. The ability of the dynamic process to adapt and create small worlds in such diverse settings suggests a possible mechanism by which such networks appear in nature

Ситуационная логика и «возможные миры»

The paper discusses the necessity to analyze the local situations in which the intellectual actions are realized. Such concepts as ‘event’ and ‘situation’ are specified. The importance of classification of situations is established. In this regard the production of human knowledge is defined as a process of describing the occurring situations. And this describing corresponds to construction of ‘possible worlds’. Evolution of concept of ‘possibility’ is observed. It is pointed out that models of ‘possible world’ are dependent on the language used for its description.В статье обсуждается необходимость анализировать локальные ситуации, в которых реализуются интеллектуальные действия. Уточняются понятия «событие» и «ситуация». Обосновывается важность классификации ситуаций. В связи с этим производство человеческих знаний характеризуется как соответствующее описание возникающих ситуаций, а само описание соотносится с построением «возможных миров». Прослеживается эволюция понятия «возможность» и рассматривается зависимость моделей «возможного мира» от используемого языка описания

A Call for a Possible World Argument in Ethics

Ethical theories must be able to deal with not only actual situations, but also counterfactual situations. By applying a possible world argument (PWA) in which we consider a theory's applicability over the space of possible worlds, we see more clearly whether the theory is world-sensitive or not (flexible or nonflexible). In this essay I will argue for the importance of PWA and show, through a case study, how different theories react to PWA. The conclusion will be open-ended: We need to have a clearer picture of moral psychology before we can settle for either a flexible or nonflexible theory in accordance with which we should live

The Situationalist Account of Change

In this paper I propose a new solution to the problem of change: situationalism. According to this view, parts of reality fundamentally disagree about what is the case and reality as a whole is unsettled (i.e. metaphysically indeterminate). When something changes, parts of the world irreconcilably disagree about what properties it has. From this irreconcilable disagreement, indeterminacy arises. I develop this picture using situations, which are parts of possible worlds; this gives it the name situationalism. It allows a B-theory endurance view on which there is genuine incompatibility when things change. There are costs to the view, which are explored, but it is a novel approach which offers a distinct explanation of what happens when things exist through change

Towards an explanation of copula effects

This paper deals with a series of semantic contrasts between the copula "be" and the preposition "as", two functional elements that both head elementary predication structures. It will be argued that the meaning of "as" is a type lowering device shifting the meaning of its complement NP from generalized quantifier type to property type (where properties are conceived as relations between individuals and situations), while the copula "be" induces a type coercion from (partial) situations to (total) possible worlds. Paired with van der Sandt's 1992 theory of presupposition accommodation, these assumptions will account for the observed contrasts between "as" and "be"