本文旨在阐明大卫·刘易斯语言哲学中的“计分”思想。刘易斯的论述对象是自然语言中除标准指代词之外具有语境敏感性的语言现象，这些表达式包括含有预设的语句、含有模糊谓词的语句、回指、省略、践言等等。为了说明这些具有语境敏感性的表达式的真值或者说可接受性，刘易斯将它们置于动态的对话中，并把这一过程比作是语言游戏中的计分过程，通过对计分过程的说明揭示这些表达式的语境敏感性。语言游戏的目的就是使对话顺利进行，因此当说者说出含有语境敏感性表达式的语句时，听者会追踪说者的首要谈论目标，并调适预设和模糊谓词的使用标准，使得说者说出的话语有真值或者可被接受，从而使得对话继续进行下去。这一过程都被记录在语言游戏中的“计分板”上，“计分板”是一个有效的语境模型。刘易斯的“计分”思想并不关注单个具有语境敏感性的表达式的真值，而是当一个含有这样的表达式的语句被说出时对整个对话所带来的影响。沿着刘易斯的思路，罗伯特·斯塔纳克发展了他的预设理论，罗伯特·布兰顿借此解释了他的道义计分的思想。

This thesis centers on David Lewis?s theory of “scorekeeping” in philosophy of language. Lewis accounts for various context-sensitivity phenomena in natural language, including pre-supposition, vagueness, anaphora, ellipses, performatives, and so on. Those context-sensitivity phenomena don?t fit readily into the neat indexical box. In order to account for the truth value or acceptability of those context-sensitivity phenomena, Lewis treats them in the course of a conversation which can be regarded as scorekeeping in a language game. Lewis reveals the context-sensitivity of these expressions by illustrating the course of keeping score. A language game is to make a conversation go smoothly. When a context-sensitivity expres-sion is contained to an utterance of a speaker, the hearer will track on direct purpose of the speaker and accommodate the presupposition or the standard of vague predicate, to make the utterance true or accepted. Thus the conversation moves on. The whole process is recorded in the “scoreboard” of the language game, which models the Linguistic context. Lewis?s theory of ?scorekeeping? focuses not on the truth value of single context-sensitivity expression, but on the changes such an expression brings about. Following Lewis, Robert Stalnaker develops the theory of presupposition, and Robert Brandom explains the deontic scorekeeping.