Administrative decisions are unlawful if they are unreasonable, in the sense that Associated Provincial Picture Houses Ltd. v Wednesbury Corporation made famous. What is Wednesbury unreasonableness, precisely? Courts have not clearly said, and existing academic answers are flawed. Here I propose a new answer. My claim, roughly, is that a Wednesbury unreasonable decision is one that a court is entitled, given the evidence before it, to conclude was wrong, given the evidence before the authority when it made the decision. In a slogan: Wednesbury unreasonableness is demonstrable wrongness.

中文翻译：

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温斯伯里的不合理

行政决定如果不合理，就是非法的，就像著名的 Associated Province Picture Houses Ltd. v Wednesbury Corporation 案一样。温斯伯里的不合理到底是什么？法院没有明确表示，现有的学术答案也存在缺陷。在这里我提出一个新的答案。粗略地说，我的主张是，温斯伯里不合理的决定是法院有权根据其面前的证据得出错误的结论，考虑到当局做出决定时所提供的证据。一句口号是：温斯伯里的不合理是明显的错误。