This article discusses the quiddity of the empty set from its epistemological and linguistic aspects. It consists of four parts. The first part compares the concept of nihil privativum and the empty set in terms of representability, arguing the empty set can be treated as a negative and formal concept. It is argued that, unlike Frege’s definition of zero, the quantitative negation with a full scope is what enables us to represent the empty set conceptually without committing to an antinomy. The second part examines the type and scope of the negation in the concept of nihil privativum and the empty set. In the third part the empty set is interpreted as a rigid abstract general term. The uniqueness of the empty set is explained via a widened version of Kripke’s notion of rigidity. The fourth part proposes a construction for the pure singleton, comparing it with Zermelo’s conception of singletons with the Ur-elements. It is argued that the proposed construction does not face the criterion and ontological inflation problems. The first conclusion of the article is that the empty set can be construed as a negative, formal and unique abstract general term, with quantitative negation full in scope. The second conclusion is that the pure singleton constructed out of the empty set construed in this way overcomes the criterion and ontological inflation problems.

本文从认识论和语言学方面讨论了空集的 quiddity。它由四部分组成。第一部分 从可表示性的角度比较了 虚无和空集的概念，认为空集可以被视为一个否定的、形式化的概念。有人认为，与弗雷格对零的定义不同，全范围的定量否定使我们能够在概念上表示空集，而无需承诺二律背反。第二部分考察了私有虚无概念中否定的类型和范围。  和空集。在第三部分，空集被解释为一个严格的抽象通用术语。空集的独特性是通过扩展版的 Kripke 刚性概念来解释的。第四部分提出了纯单例的构造，将其与 Zermelo 的带有 Ur 元素的单例概念进行了比较。有人认为，所提出的结构不面临标准和本体膨胀问题。文章的第一个结论是，空集可以被理解为一个否定的、形式化的、独特的抽象一般术语，具有全范围的定量否定。第二个结论是，从以这种方式解释的空集构建的纯单例克服了标准和本体论膨胀问题。