It is a recurring idea in the history of political philosophy that concepts and doctrines of private law are illuminative of public law and political philosophy. Central among these are contract (especially) and the trust. In this paper, I consider the prospects of a third: estoppel. The public law context in which estoppel is most commonly invoked is criminal law, and there especially in the service of understanding the defenses of entrapment and what I call officially induced mistake of law (OIML). My question is how well it serves this role – how well the structure of the self-disentitlement that provides the rationales for the defences of entrapment and OIML on the non-exculpatory approach to each is articulated on the model of state estoppel, as I call it. I will argue that it fares well, and so that estoppel merits inclusion on the list of concepts and doctrines of private law that are illuminative of public law and political philosophy. In conclusion I will ask what the moral-expressive content of its deployment in that context is, and argue that, while the doctrines of contract and trust work as means to articulate claims about the basis and limit of political authority, the claim that some cases of state self-disentitlement can be modelled on estoppel represents a commitment to some core principles of the rule of law.

中文翻译：

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国家禁止反言

私法的概念和学说对公法和政治哲学具有启发性，这是政治哲学史上反复出现的观点。其中的核心是合同（特别是）和信任。在本文中，我考虑了第三种的前景：禁止反言。禁止反言最常被援引的公法背景是刑法，尤其是在理解陷阱辩护和我所谓的官方诱发的法律错误 (OIML) 方面。我的问题是它如何很好地发挥了这个作用——为诱捕辩护和 OIML 对每个人的非无罪辩护方法提供理由的自我剥夺权利的结构在国家禁止反言模型上的表达有多好，正如我所说的它。我会争辩说它很好，因此，禁止反言值得列入对公法和政治哲学具有启发意义的私法概念和学说清单。最后，我将询问在这种情况下其部署的道德表达内容是什么，并论证说，虽然契约和信任的学说作为阐明关于政治权威的基础和限制的主张的手段，但某些情况下的主张国家自我剥夺权利可以模仿禁止反言代表对法治的一些核心原则的承诺。