Cooperation,Knowledge, and Time: Alternating-time Temporal Epistemic Logic and its Applications

Branching-time temporal logics have proved to be an extraordinarily successful tool in the formal specification and verification of distributed systems. Much of their success stems from the tractability of the model checking problem for the branching time logic CTL, which has made it possible to implement tools that allow designers to automatically verify that systems satisfy requirements expressed in CTL. Recently, CTL was generalised by Alur, Henzinger, and Kupferman in a logic known as Alternating-time Temporal Logic (ATL). The key insight in ATL is that the path quantifiers of CTL could be replaced by cooperation modalities, of the form , where is a set of agents. The intended interpretation of an ATL formula is that the agents can cooperate to ensure that holds (equivalently, that have a winning strategy for ). In this paper, we extend ATL with knowledge modalities, of the kind made popular in the work of Fagin, Halpern, Moses, Vardi and colleagues. Combining these knowledge modalities with ATL, it becomes possible to express such properties as group can cooperate to bring about iff it is common knowledge in that . The resulting logic — Alternating-time Temporal Epistemic Logic (ATEL) — shares the tractability of model checking with its ATL parent, and is a succinct and expressive language for reasoning about game-like multiagent systems.     

Manifestability and Epistemic Truth

I argue that the standard anti-realist argument from manifestability to intuitionistic logic is either unsound or invalid. Strong interpretations of the manifestability of understanding are falsified by the existence of blindspots for knowledge. Weaker interpretations are either too weak, or gerrymandered and ad hoc. Either way, they present no threat to classical logic.     

Skepticism and Epistemic Logic

This essay attempts to implement epistemic logic through a non-classical inference relation. Given that relation, an account of '(the individual) a knows that A' is constructed as an unfamiliar non-normal modal logic. One advantage to this approach is a new analysis of the skeptical argument.     

Testimony,Knowledge, and Epistemic Goals

Various considerations are adduced toshow that we require that a testifier know hertestimony. Such a requirement apparentlyimproves testimony. It is argued that the aimof improving testimony explains why we have anduse our concept of knowledge. If we were tointroduce a term of praise for testimony, usingit at first to praise testimony that apparentlyhelped us in our practical projects, it wouldcome to be used as we now use the word``know'.     

Williamson on Gettier Cases and Epistemic Logic

Abstract

Timothy Williamson has fruitfully exploited formal resources to shed considerable light on the nature of knowledge. In the paper under examination, Williamson turns his attention to Gettier cases, showing how they can be motivated formally. At the same time, he disparages the kind of justification he thinks gives rise to these cases. He favors instead his own notion of justification for which Gettier cases cannot arise. We take issue both with his disparagement of the kind of justification that figures in Gettier cases and the specifics of the formal motivation.     

Knowledge,Truth and Plausibility

From antiquity several philosophers have claimed that the goal of natural science is truth. In particular, this is a basic tenet of contemporary scientific realism. However, all concepts of truth that have been put forward are inadequate to modern science because they do not provide a criterion of truth. This means that we will generally be unable to recognize a scientific truth when we reach it. As an alternative, this paper argues that the goal of natural science is plausibility and considers some characters of plausibility.     

Ignorance,Knowledge, and Two Epistemic Intuitions

Philosophia - One of the most venerable and enduring intuitions in epistemology concerns the relationship between true belief and knowledge. Famously articulated by Socrates, it holds that true...     

Constructive Logic, Truth and Warranted Assertability

Shapiro and Taschek have argued that simply using intuitionistic logic and its Heyting semantics, one can show that there are no gaps in warranted assertability. That is, given that a discourse is faithfully modelled using Heyting's semantics for the logical constants, then if a statement S is not warrantedly assertable, its negation ^∼ S is. Tennant has argued for this conclusion on similar grounds. I show that these arguments fail, albeit in illuminating ways. An appeal to constructive logic does not commit one to this strong epistemological thesis, but appeals to semantics of intuitionistic logic none the less do give us certain conclusions about the connections between warranted assertability and truth.     

Aiming at Truth: Doxastic vs. Epistemic Goals

Belief is generally thought to be the primary cognitive state representing the world as being a certain way, regulating our behavior and guiding us around the world. It is thus regarded as being constitutively linked with the truth of its content. This feature of belief has been famously captured in the thesis that believing is a purposive state aiming at truth. It has however proved to be notoriously difficult to explain what the thesis really involves. In this paper, I begin by critically examining a number of recent attempts to unpack the metaphor. I shall then proceed to highlight an error that seems to cripple most of these attempts. This involves the confusion between, what I call, doxastic and epistemic goals. Finally, having offered my own positive account of the aim-of-belief thesis, I shall underline its deflationary nature by distinguishing between aiming at truth and hitting that target (truth). I end by comparing the account with certain prominent inflationary theories of the nature of belief. I am grateful to Muhammed Legenhausen, David Velleman and an anonymous referee of this journal for helpful comments on earlier drafts of this paper.     

人类对知识的好奇:认识性好奇心

认识性好奇心是个体对新知识的好奇,可从状态和特质角度理解,其中特质认识性好奇心又区分为兴趣型和剥夺型两种类型。近年来众多证据表明,认识性好奇心受知道感、性别、对信息的偏好模式等因素影响,并在学习、记忆及创造性方面起到积极作用。未来研究有必要着眼于毕生发展的角度进行纵向考察,完善其测量方式,并深入考察认识性好奇心对学习的影响机制,从而为教育实践提供一定启示。