# Pascal’s Wager

> 【EN】“Pascal’s Wager” is the name given to an argument due to Blaise Pascal for believing, or for at least taking steps to believe, in God. The name is somewhat misleading, for in a single section of his Pensées , Pascal apparently presents four such arguments, each of which might be called a ‘wager’—it is only the third of these that is traditionally referred to as “Pascal’s Wager”. We find in it the extraordinary confluence of several important strands of thought: the justification of theism; probability theory and decision theory, used here for almost the first time in history; pragmatism; voluntarism (the thesis that belief is a matter of the will); and the use of the concept of infinity. We will begin with some brief stage-setting: some historical background, some of the basics of decision theory, and some of the exegetical problems that the Pensées pose. … 【中】词条考察这一论证的几种形式：优势论证主张信上帝在任何情形下都不吃亏；期望论证则诉诸无穷大的收益，认为无论上帝存在的概率多小，乘以无穷的奖赏后期望值都压倒一切。文中逐条检视其前提，包括上帝存在的概率赋值、理性是否要求最大化期望效用、论证是否有效，以及为得救而下注是否违背道德真诚。

- ID: m13274
- Category: culture
- Domain: 伦理学

## Definition

帕斯卡的赌注是帕斯卡为相信上帝、或至少为采取步骤去相信上帝而提出的一组论证。传统上这个名称指《思想录》中四个类似论证的第三个，它汇聚了神学辩护、概率与决策理论、实用主义、意志主义与无穷概念等线索。 脚手架作用：- 极端决策：用期望值框架处理后果悬殊且不可逆的选择，如信仰与生死。 - 假设审计：检验结论是否依赖无穷奖赏，换成有限值后是否还成立。

## How it works

机制是决策论的期望值计算：把信与不信两种行动，乘以上帝存在与不存在两种状态。只要把奖赏取为无穷，且概率不为零，任何有限代价都无法与之竞争；一旦放弃无穷，结论便不再稳固，这也解释了后世的诸多修正。

## Practice

1) 写出行动与状态的收益矩阵；2) 检查是否真的应把奖赏视为无穷大；3) 追问极小的概率能否被可靠地赋值；4) 检验相信可由意志决定这一前提；5) 评估结论对所用决策规则的敏感度。

## Use

- 极端决策：用期望值框架处理后果悬殊且不可逆的选择，如信仰与生死。 - 假设审计：检验结论是否依赖无穷奖赏，换成有限值后是否还成立。

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