We know things about the world in spite of our cognitive limitations and imperfections. Occasions of stress impact memory retrieval, resources for attention can be depleted by non-epistemic factors, and our visual system has limited resolution and discriminatory ability. Yet we know many propositions, ranging from the mundane to the arcane, and we often are able to know that we know these things. In this dissertation I explore the relationship between our cognitive limitations and the limits to what we know, and what we know that we know. I begin by considering a simple model of knowledge. Because it is difficult (perhaps impossible) to have intuitions about many higher-order or iterative knowledge claims ("I know that you know that she knows that I know that ..."), a modeling approach can help clarify and explain how various cognitive limitations impact knowledge and higher-order knowledge. In Chapter 2 I discuss the epistemic requirements for the rational coordination of our actions. While it may seem that coordination is rational only if each coordinating member has what may be called "common knowledge" of some relevant proposition, the model of knowledge I employ helps show the informational complexity of common knowledge. I argue that common knowledge is unattainable. In Chapter 3 I discuss epistemic closure. Perfectly ideal agents may know every deductive consequence of what they know, but if the aim is to understand how deduction extends human knowledge then it is necessary to model our cognitive access to information. In Chapter 4 I turn to the issue of higher-order or iterative knowledge. I argue that memory limitations and various information processing errors all result in failures of higher-order knowledge. The argument I give does not require epistemic closure or a principle of self-knowledge. I conclude, in Chapter 5, by discussing interpretive issues for models of knowledge and I discuss our awareness of what we know and what we do not know.

西方哲學中的知識論就著知識的本質、知識之範圍、知識成立的條件等等問題有著深入而又精微的討論，然而反觀中國古代的先秦儒者，他們所關懷往往是內聖外王之事，且拙於運用抽象的概念進行思考，因此他們從不曾顯題化地對知識之構造、本質等等進行嚴謹而有系統的思考。然而，人一旦廁身於世，就無可避免地面對認識的問題，而無論是甚麼人，都有運用自己的感官和理性思維去認識、理解世界的經驗，因此假使我們仔細閱讀先秦儒者對於「知」的零碎文本，未嘗不可建立一套先秦儒者的「知」「識」論。 / 因此，本文將以孔子、孟子、荀子的文本為主要探討對象，分析他們所言之「知」「識」的各種意涵，具體的論述將主要分為四章：第一章「耳目之知」，闡述先秦儒者對於運用各種身體感官以認識外物的討論；第二章則為「知慮之知」，以理性思維能力為探討核心；第三章則為「知義之知」，探討在孟荀理解中，道德是如何被認識；而最後一章是「知天之知」，研究「天」、「命」這兩個觀念在孟荀文本中，是如何被理解和掌握的。本研究希望通過重新梳理「知」之不同層次之意涵，重構先秦儒者對於知識的討論，雖然當中或沒有令人耳目一新之創見，但望能為日後進一步討論作基石。 / Western epistemology has flourish, thorough discussion on the nature, scope, necessary and sufficient conditions of knowledge. For Pre-Qin Confucians, as what they concerned about were how to be a sage and true king and they were weak in conceptual thinking, thus they did not have any thematic and systematic discussion on the issue of the nature and structure of knowledge. However, everyone encounters the problem of how to get to know the outside world when they are living. Besides this, everyone has the experience of using their sense organs and rationality to perceive and understand the world. As a result, although Pre-Qin Confucians has only some piecemeal texts on knowing, we can still re-construct their views on knowing through detailed, deep analysis of their words. / As a result, this research will focus on Confucius, Mencius and Xunzi, analyzing different meanings of "Zhi" "Shi" (knowledge) in their texts. It will divide into four main parts, chapter one will concentrate on the discussion of sensible knowing, while chapter two will reveal the kind of knowing by rational deliberation and inference. As for chapter three, it will study how morality is being acquired in Mencius and Xunzi’s thought. Then the last chapter will examine some transcendental objects, such as "tian" and "ming", are how to be perceived. After all, despite this research might not contain much insightful, new opinions, its clarification and division on the meaning of "Zhi" might serve as a helpful ground for further discussion on the thought of knowing in Chinese Philosophy. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / 葉德莉. / Thesis (M.Phil.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 143-146). / Abstracts in Chinese and English. / Ye Deli.

In my dissertation I develop and defend a deliberative account of causation: causal relations correspond to the evidential relations we use when we decide on one thing in order to achieve another. Tamsin’s taking her umbrella is a cause of her staying dry, for example, if and only if her deciding to take her umbrella for the sake of staying dry is adequate grounds for believing she’ll stay dry. I defend the account in the form of a biconditional that relates causal relations to evidential relations. This biconditional makes claims about causal relations, not just our causal concepts, and constrains metaphysical accounts of causation, including reductive ones. Surely we need science to investigate causal structure. But we can’t justify any particular account of causation independently of its relevance for us. This deliberative account explains why we should care about causation, why we deliberate on the future and not the past, and even why causes come prior in time to their effects. In chapter 1 I introduce the motivations for the project: to reconcile causation and our freedom as agents with the picture of the world presented by physics. Fundamental physics makes no mention of causes. And the lawlike character of the world seems to rule out freedom to decide. My dissertation offers a combined solution—I explain our freedom in epistemic terms and use this freedom to make sense of causation. In chapter 2 I draw on philosophy of action and decision theory to develop an epistemic model of deliberation, one based in requirements on belief. If we’re to deliberate, our beliefs can’t epistemically settle how we’ll decide, yet our decisions must epistemically settle what we’ll do. This combination of belief and suspension of belief explains why we rationally take ourselves to be free to decide on different options in deliberation. In chapter 3 I defend this model from near rivals that also explain freedom in terms of belief. Accounts of ‘epistemic freedom’ from David Velleman, James Joyce and Jenann Ismael appeal to our justification to form beliefs ‘unconstrained’ by evidence. Yet, I will argue, these accounts are susceptible to counterexamples and turn out to rely on a primitive ability to believe at will—one that makes the appeal to justification redundant. J. G. Fichte’s Idealist account of freedom, based in a primitive activity of the ‘I’, nicely illustrates the kind of freedom these accounts rely on. In chapter 4 I develop the epistemic model of deliberation into a deliberative account of causation. I argue that A is a type-level cause of B if and only if an agent deciding on a state of affairs of type A in ‘proper deliberation’, for the sake of a state of affairs of type B would be good evidence of a state of affairs of type B obtaining. This biconditional explains why we should care about causal relations—they direct us to good decisions. But existing accounts of causation don’t adequately explain why causation matters. James Woodward’s interventionist account explicates ‘control’ and ‘causation’ in the very same terms—and so can’t appeal to a relation between them to explain why we should care about causal relations. David Lewis’ reductive account relies on standards for evaluating counterfactuals, but doesn’t motivate them or explain why a causal relation analysed in these terms should matter. Delivering the right verdicts is not enough. The deliberative account explains why causation matters, by relating causal relations to the evidential relations needed for deliberation. In chapter 5 I use the deliberative account to explain causal asymmetry—why, contingently, causes come before their effects. Following an approach from Huw Price, because deliberation comes prior to decision, deliberation undermines evidential relations towards the past. So an agent’s deciding for the sake of the past in proper deliberation won’t be appropriate evidence of the past, and backwards causation is not implied. To explain why deliberation comes prior to decision, I appeal to an epistemic asymmetry, one that is explained by statistical-mechanical accounts of causation in non-causal terms. But statistical-mechanical accounts still need the deliberative account to justify why the relations they pick out as causal should matter to us. The deliberative account of causation relates causal relations to the evidential relations of use to deliberating agents. It constrains metaphysical accounts, while revealing their underlying explanatory structure. And it does not rule out explanations of causal asymmetry based in physics, but complements them. Overall this project makes sense of causation by foregrounding its relevance for us.

The goal of this dissertation is to give a logical representation of the knowledge dynamics that takes place during communication. I present a number of di erent logical frameworks for a number of di erent scenarios, ranging from an email conversation where all information that is sent is considered to be true, to a game of Liar's Dice where lying is expected of the players. In Chapter 3, I present a framework for modeling the knowledge of agents who exchange messages, using Dynamic Epistemic Logic. This framework uses Kripke models to represent the agents' knowledge in a static situation, and action models to update these Kripke models when the situation changes. Because the models are supposed to be nite, and all messages are represented explicitly in the model, the messages that are considered possible by the agents are limited to a nite set. This framework is useful in a situation in which there is a number of rounds in each of which a nite set of new messages becomes available to the agents. These messages can gradually be added to the model. The framework presented in Chapter 4 is of a more general nature. It models a setting where agents communicate with messages over a speci fic network in accordance to a certain protocol. This framework is very exible because the nature of communicative events and the observational power of the agents can be adapted to the situation at hand. It combines properties of the Dynamic Epistemic Logic approach with the perspective of Interpreted Systems. In Chapter 5 and 6 I focus on email communication speci cally. I rst study the existence of common knowledge in a group of agents who communicate via emails. Unlike the approach presented in Chapter 3, all possible emails are rep- resented in the model, which is therefore of in nite size. I prove a number of properties of nite states in this in nite model, and show that common knowledge of an email with BCC recipients is rare. Apart from common knowledge, I consider two new kinds of knowledge: potential and de nitive knowledge. These two types of knowledge make a distinction between the assumption that every agent immediately reads every email he receives, or that every agent has only read the emails he replied to or forwarded. I also present a method to do model checking, even though the model is of in nite size. Chapter 7 is a study of the properties of action models, which are used to model communicative events. I de ne a notion of action emulation that signi es when two canonical action models are equivalent. Because every action model has an equivalent canonical action model which can be computed, this gives a general method to determine action model equivalence. In Chapter 8 I move from knowledge to belief. I use the same Kripke models as for knowledge, only without the assumption that all relations are equivalence relations. I propose a di erent assumption, namely that the relations are linked. I also give a number of updates of these models that preserve this property, representing communicative events. Finally, Chapter 9 gives di erent perspectives on the issue of lying. It includes a complete logic of manipulative updating, which can be used to represent the e ects of lying in a group of agents. I also analyze a game of Liar's Dice and implement this scenario in the model checker DEMO. Furthermore, I show that in a game where lying is considered normal, a lie is no longer a lie: because the agents who hear the lie do not believe it, no false belief is created.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23687号 / 理博第4777号 / 新制||理||1684(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 長谷川 真人, 教授 牧野 和久, 准教授 照井 一成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Dans cette thèse, nous proposons des modèles logiques pour la représentation des croyances et leur changement dans un cadre multi-agent, en insistant sur l'importance de se fixer un point de vue particulier pour la modélisation. A cet égard, nous distinguons deux approches différentes: l'approche externe, où le modélisateur est quelqu'un d'externe à la situation; l'approche interne, où le modélisateur est l'un des agents. Nous proposons une version interne de la logique épistémique dynamique (avec des modèles d'événements), ce qui nous permet de généraliser facilement la théorie de la révision des croyances d'AGM au cas multi-agent. Ensuite, nous mod´elisons les dynamismes logiques complexes qui soustendent notre interprétation des événements en introduisant des probabilités et des infinitésimaux. Finalement, nous proposons un formalisme alternatif qui n'utilise pas de modèle d'événement mais qui introduit à la place un opérateur d'événement inverse.

The purpose of this work is to investigate how processes of inference are reflected in the grammar of the natural language. I consider a range of phenomena which call for a representational theory of mind and thought. These constructions display a certain regularity in their truth conditions, but the regularity does not extend to closure under arbitrary logical entailment. I develop a logic that allows me to speak formally about classes of inferences. This logic is then applied to analysis of indirect speech, belief reports, evidentials (with special attention to Bulgarian) and clarity assertions. / text

We propose in the paper a new solution to the so-called Logical Omniscience Problem of epistemic logic. Almost all attempts in the literature to solve this problem consist in weakening the standard epistemic systems: weaker systems are considered where the agents do not possess the full reasoning capacities of ideal reasoners. We shall argue that this solution is not satisfactory: in this way omniscience can be avoided, but many intuitions about the concepts of knowledge and belief get lost. We shall show that axioms for epistemic logics must have the following form: if the agent knows all premises of a valid inference rule, and if she thinks hard enough, then she will know the conclusion. To formalize such an idea, we propose to \dynamize' epistemic logic, that is, to introduce a dynamic component into the language. We develop a logic based on this idea and show that it is suitable for formalizing the notion of actual, or explicit knowledge.

La notion de système de contraintes (cs – selon l'acronyme anglais) est un concept central aux formalismes de la théorie de la concurrence tels que les algèbres de processus pour la programmation concurrente par contraintes. Les systèmes de contraintes sont souvent représentés par des treillis : ses éléments, appelées contraintes, représentent des informations partiales tandis que l’ordre du treillis correspond à des implications. Récemment, une notion appelée “système de contraintes spatiales à n-agents” a été développée pour représenter l’information dans la programmation concurrente par contraintes où les systèmes sont multi-agents et spatialement distribués.D’un point de vue informatique, un système de contraintes spatiales peut être utilisé pour spécifier l’information partiale contenue dans l'espace d'un certain agent (information locale). D’un point de vue épistémique, un cs spatial peut être utilisé pour représenter l’information qui est considérée vrai pour un certain agent (croyance). Les systèmes de contraintes spatiales, néanmoins, ne fournissent pas de mécanismes pour la spécification de la mobilité de l’information ou des processus d'un espace à un autre. La mobilité de l’information est un aspect fondamental des systèmes concurrents.Dans cette thèse nous avons développé la théorie des systèmes de contraintes spatiales avec des opérateurs pour spécifier le déplacement des informations et processus entre les espaces. Nous étudions les propriétés de cette nouvelle famille de systèmes de contraintes et nous illustrons ses applications.Du point de vue calculatoire, ces nouveaux opérateurs nous apportent de l’extrusion d’informations et/ou des processus, qui est un concept central dans les formalismes pour la communication mobile. Du point de vue épistémique, l’extrusion correspond à une notion que nous avons appelé énonciation ; une information qu’un agent souhaite communiquer à d'autres mais qui peut être inconsistante avec les croyances de l’agent même. Des énonciations peuvent donc être utilisées pour exprimer des notions épistémiques tels que les canulars ou les mensonges qui sont fréquemment utilisés dans les réseaux sociaux.Globalement, les systèmes de contraintes peuvent exprimer des notions épistémiques comme la croyance/énonciation et la connaissance en utilisant respectivement une paire de fonctions espace/extrusion qui représentent l’information locale, et un opérateur spatial dérivé qui représente l’information globale. Par ailleurs, nous montrons qu’en utilisant un type précis de systèmes de contraintes nous pouvons aussi représenter la notion du temps comme une séquence d'instances. / The notion of constraint system (cs) is central to declarative formalisms from concurrency theory such as process calculi for concurrent constraint programming (ccp). Constraint systems are often represented as lattices: their elements, called constraints, represent partial information and their order corresponds to entailment. Recently a notion of n-agent spatial cs was introduced to represent information in concurrent constraint programs for spatially distributed multi-agent systems. From a computational point of view a spatial constraint system can be used to specify partial information holding in a given agent’s space (local information). From an epistemic point of view a spatial cs can be used to specify information that a given agent considers true (beliefs). Spatial constraint systems, however, do not provide a mechanism for specifying the mobility of information/processes from one space to another. Information mobility is a fundamental aspect of concurrent systems.In this thesis we develop the theory of spatial constraint systems with operators to specify information and processes moving between spaces. We investigate the properties of this new family of cs and illustrate their applications. From a computational point of view the new operators provide for process/information extrusion, a central concept in formalisms for mobile communication. From an epistemic point of view extrusion corresponds to what we shall call utterance; information that an agent communicates to others but that may be inconsistent with the agent’s beliefs. Utterances can be used to express instances of epistemic notions such as hoaxes or intentional lies which are common place in social media.On the whole, constraint systems can express the epistemic notions of belief /utterance and knowledge by means of, respectively, a space/extrusion function pair that specifies local information and a derived spatial operator that specifies global information. We shall also show that, by using a specific kind of our constraint systems, we can also encode the notion of time as a sequence of instances.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20159号 / 理博第4244号 / 新制||理||1610(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 照井 一成, 教授 岡本 久, 教授 長谷川 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM