Recently, a number of metaphysicians have been working on the issue of the metaphysical grounds of identity facts. In this paper, I will survey a variety of accounts of identity facts through a particular lens. These accounts will be examined in light of the so-called ‘purity’ principle, a principle intriguing many discussions on metaphysical grounding in recent literature. The aim of this paper is twofold. First, I will indicate what sorts of accounts of identity facts the purity principle rules out and what sorts of accounts it allows. Secondly, I will pinpoint some patterns of how the purity principle may interact with first-order metaphysical inquiries in general.

中文翻译：

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身份和纯度

最近，一些形而上学家一直在研究身份事实的形而上学基础问题。在本文中，我将通过一个特定的镜头来调查各种关于身份事实的说明。这些叙述将根据所谓的“纯粹性”原则进行审查，这一原则在最近的文献中引起了许多关于形而上学基础的讨论。本文的目的是双重的。首先，我将说明纯度原则排除了哪些类型的身份事实说明以及它允许​​哪些类型的说明。其次，我将指出纯度原则如何与一般的一阶形而上学探究相互作用的一些模式。