We suggest that the issue of constructing andverifying social procedures, which we suggestively call socialsoftware, be pursued as systematically as computer software is pursued by computer scientists. Certain complications do arise withsocial software which do not arise with computer software, but thesimilarities are nonetheless strong, and tools already exist which wouldenable us to start work on this important project. We give a variety ofsuggestive examples and indicate some theoretical work which alreadyexists.

Editorial Rohit Parikh, Jeffrey Helzner, Episteme, FirstView Article.

Aversive autobiographical memories sometimes prompt maladaptive emotional responses and contribute to affective dysfunction in anxiety and depression. One way to regulate the impact of such memories is to create a downward counterfactual thought–a mental simulation of how the event could have been worse–to put what occurred in a more positive light. Despite its intuitive appeal, counterfactual thinking has not been systematically studied for its regulatory efficacy. In the current study, we compared the regulatory impact of downward counterfactual thinking, temporal distancing, (...) and memory rehearsal in 54 adult participants representing a spectrum of trait anxiety. Participants recalled regretful experiences and rated them on valence, arousal, regret, and episodic detail. Two to six days later, they created a downward counterfactual of the remembered event, thought of how they might feel about it 10 years from now, or simply rehearsed it. A day later, participants re-rated the phenomenological characteristics of the events. Across all participants, downward counterfactual thinking, temporal distancing, and memory rehearsal were equally effective at reducing negative affect associated with a memory. However, in individuals with higher trait anxiety, downward counterfactual thinking was more effective than rehearsal for reducing regret, and it was as effective as distancing in reducing arousal. We discuss these results in light of the functional theory of counterfactual thinking and suggest that they motivate further investigation into downward counterfactual thinking as a means to intentionally regulate emotional memories in affective disorders. (shrink)

Each of us has a story which we can think of as a set of beliefs, hopefully consistent. We make our decisions in view of our beliefs which may be probabilistic, in the general case, but simple yes or no as in this paper. Our beliefs are our envelope just as the shell of a tortoise is its envelope. Decision theory—or single agent game theory tells us when to make the best choice in a game of us against nature. But (...) nature has no desire to further or frustrate our efforts. Nature is mysterious but not malign. Things change when there are other agents involved. Then the best thing for us to do will depend on what they do. And they will think the same. And we predict their actions in terms of what we think their beliefs are. But how do we coordinate with others whose beliefs are different? This paper addresses the issue of working together despite different beliefs. (shrink)

The primary function of language is communication. We use the tools of situation theory and game theory to develop a definition and model of communication between rational agents using a shared situated language. ;A central thesis of this dissertation is that the key feature of situated communication that enables agents to derive content from meaning is a special type of logical inference called a strategic inference. ;The model we develop, called the Strategic Discourse Model, looks at a single strategic inference. (...) An essential element of a strategic inference is that the content depends on the sentence uttered and on the embedding circumstances. This includes the private and public information and beliefs of the agents, their goals and intentions, and crucially, the other sentences the speaker might have uttered but chose not to. A complete model of communication involves a system of simultaneous strategic inferences. ;When the strategic interaction between two agents is common knowledge between them, that is, when it is a game, the information transfer is a communication. The content communicated is given by the solution to the game. This analysis formalizes Grice's ideas on nonnatural meaning within a situation-theoretic framework. A consequence of our situated analysis is that agents do not need to have the complex and infinite set of nested intentions postulated by the Gricean approach. A simple intention to communicate is all that is required, the ambient game doing the rest of the work. ;This model has many applications. Problems like resolving ambiguity, determining reference, inferring implicatures and indirect speech acts fall within its scope. As one application, we outline a new theory of names and definite descriptions. This account builds upon Russell and Strawson, and Barwise and Perry. The basic idea is that names and descriptions can both be used in various ways circumscribed by an ontological and a communicative constraint. This offers a new solution to the puzzle of informative identity statements and clarifies the referential-attributive distinction. It suggests an approach to the concept of representation. ;An underlying theme is to synthesize situation theory and game theory. (shrink)

In Language and Equilibrium, Prashant Parikh offers a new account of meaning for natural language. He argues that equilibrium, or balance among multiple interacting forces, is a key attribute of language and meaning and shows how to derive the meaning of an utterance from first principles by modeling it as a system of interdependent games.His account results in a novel view of semantics and pragmatics and describes how both may be integrated with syntax. It considers many aspects of meaning--including (...) literal meaning and implicature--and advances a detailed theory of definite descriptions as an application of the framework.Language and Equilibrium is intended for a wide readership in the cognitive sciences, including philosophers, linguists, and artificial intelligence researchers as well as neuroscientists, psychologists, and economists interested in language and communication. (shrink)

I want to start by giving some quotes from Wittgenstein. It is part of his conception of what the foundations of Mathematics are about, a conception which many people have found peculiar and one of my defects is that I am not able to find it peculiar anymore, but find it perfectly sensible.

Counterfactual thinking, or simulating alternative versions of occurred events, is a common psychological strategy people use to process events in their lives. However, CFT is also a core com...

Communication and content presents a comprehensive and foundational account of meaning based on new versions of situation theory and game theory. The literal and implied meanings of an utterance are derived from first principles assuming little more than the partial rationality of interacting agents. New analyses of a number of diverse phenomena – a wide notion of ambiguity and content encompassing phonetics, syntax, semantics, pragmatics, and beyond, vagueness, convention and conventional meaning, indeterminacy, universality, the role of truth in communication, semantic (...) change, translation, Frege’s puzzle of informative identities – are developed. Communication, speaker meaning, and reference are defined. Frege’s context and compositional principles are generalized and reconciled in a fixed-point principle, and a detailed critique of Grice, several aspects of Lewis, and some aspects of the Romantic conception of meaning are offered. Connections with other branches of linguistics, especially psycholinguistics, sociolinguistics, historical linguistics, and natural language processing, are explored. -/- The book will be of interest to scholars in philosophy, linguistics, artificial intelligence, and cognitive science. It should also interest readers in related fields like literary and cultural theory and the social sciences. (shrink)

In his deeply personal yet academically rigorous book, The Ethics of Oneness: Emerson, Whitman, and the Bhagavad Gita, Jeremy Engels takes up the task of describing and critiquing the quintessential U.S. American philosophies of Ralph Waldo Emerson and Walt Whitman. Though much ink has been spilled over these two philosophers, there are two features of Engels approach to their description and critique that make it unique when compared with other books that delve into the history of Indian philosophy’s influence on (...) these American philosophers. Engels’ purpose is not simply to recount the history, but rather to explicate Emerson and Whitman’s philosophies in light of that history in a way that makes them relevant to... (shrink)

Both the Beth definability theorem and Craig's lemma (interpolation theorem from now on) deal with the issue of the entanglement of one language L1 with another language L2, that is to say, information transfer—or the lack of such transfer—between the two languages. The notion of splitting we study below looks into this issue. We briefly relate our own results in this area as well as the results of other researchers like Kourousias and Makinson, and Peppas, Chopra and Foo.Section 3 does (...) contain one apparently new theorem. (shrink)

We investigate the semantics of messages, and argue that the meaning ofa message is naturally and usefully given in terms of how it affects theknowledge of the agents involved in the communication. We note thatthis semantics depends on the protocol used by the agents, and thus not only the message itself, but also the protocol appears as a parameter in the meaning. Understanding this dependence allows us to give formal explanations of a wide variety of notions including language dependence, implicature, (...) and the amount of information in a message. (shrink)

We offer a probabilistic model of rational consequence relations (Lehmann and Magidor, 1990) by appealing to the extension of the classical Ramsey-Adams test proposed by Vann McGee in (McGee, 1994). Previous and influential models of nonmonotonic consequence relations have been produced in terms of the dynamics of expectations (Gärdenfors and Makinson, 1994; Gärdenfors, 1993).'Expectation' is a term of art in these models, which should not be confused with the notion of expected utility. The expectations of an agent are some form (...) of belief weaker than absolute certainty. Our model offers a modified and extended version of an account of qualitative belief in terms of conditional probability, first presented in (van Fraassen, 1995). We use this model to relate probabilistic and qualitative models of non-monotonic relations in terms of expectations. In doing so we propose a probabilistic model of the notion of expectation. We provide characterization results both for logically finite languages and for logically infinite, but countable, languages. The latter case shows the relevance of the axiom of countable additivity for our probability functions. We show that a rational logic defined over a logically infinite language can only be fully characterized in terms of finitely additive conditional probability. (shrink)

We give an example of a polynomial time algorithm for a particular algorithmic problem involving vagueness and visual indiscriminability, namely sock sorting.

We propose a model for belief which is free of presuppositions. Current models for belief suffer from two difficulties. One is the well known problem of logical omniscience which tends to follow from most models. But a more important one is the fact that most models do not even attempt to answer the question what it means for someone to believe something, and justwhatit is that is believed. We provide a flexible model which allows us to give meaning to beliefs (...) in general contexts, including the context of animal belief (where action is usually our only clue to a belief), and of human belief which is expressed in language. (shrink)

Game Logic is a modal logic which extends Propositional Dynamic Logic by generalising its semantics and adding a new operator to the language. The logic can be used to reason about determined 2-player games. We present an overview of meta-theoretic results regarding this logic, also covering the algebraic version of the logic known as Game Algebra.

This paper extends Parikh's earlier work in semantics with games of partial information and attempts to derive and represent the full content of an utterance from first principles. It also discusses various ways in which this content may be indeterminate.

Whenever health care reform is debated, the state of the medical professional liability system in the United States re-emerges as an issue of importance. What exactly is broken with the MPL system and what the implications are is a point of contention among different stakeholder groups. Recent data demonstrate that medical liability premiums have been improving in recent years and the majority of premiums remained flat in 2010. General agreement still exists, however, that medical professional liability insurance premiums have become (...) unaffordable for many physicians, and coverage has become less available, especially for certain medical specialties and in specific areas of the country.Multiple factors go into the determination of medical professional liability insurance premiums including return on investments, reinsurance costs, claims frequency, average amount paid out on malpractice claims, defense expenses, and administrative costs such as underwriting expense. (shrink)

Supercommentary, with commentaries on Praśastapādabhāṣya, a work on Kaṇāda's Vaiśeṣikasūtra, treatise on the Vaiśeṣika school in Hindu philosophy.

In strategic situations, agents base actions on knowledge and beliefs. This includes knowledge about others’ strategies and preferences over strategy profiles, but also about other external factors. Bernheim and Pearce in 1984 independently defined the game theoretic solution concept of rationalizability, which is built on the premise that rational agents will only take actions that are the best response to some situation that they consider possible. This accounts for other agents’ rationality as well, limiting the strategies to which a particular (...) agent must respond, enabling further elimination until the strategies stabilize. We seek to generalize rationalizability to account not only for actions, but knowledge of the world as well. This will enable us to examine the interplay between action based and knowledge based rationality. We give an account of what it means for an action to be rational relative to a particular state of affairs, and in turn relative to a state of knowledge. We present a class of games, Epistemic Messaging Games, with a communication stage that clarifies the epistemic state among the players prior to the players’ actions. We use a history based model, which frames individual knowledge in terms of local projections of a global history. With this framework, we give an account of rationalizability for subclasses of EMG. (shrink)

Subset Spaces were introduced by L. Moss and R. Parikh in [8]. These spaces model the reasoning about knowledge of changing states.In [2] a kind of subset space called intersection space was considered and the question about the existence of a set of axioms that is complete for the logic of intersection spaces was addressed. In [9] the first author introduced the class of directed spaces and proved that any set of axioms for directed frames also characterizes intersection spaces.We (...) give here a complete axiomatization for directed spaces. We also show that it is not possible to reduce this set of axioms to a finite set. (shrink)