This paper argues that true singular existentials are rationally indubitable. After the claim is clarified and motivated (Section 1), it is defended against objections inspired by Cartesian skepticism and semantic externalism (Section 2), a Fregean fine-grained conception of propositional content (Section 3), Kripke's causal theory of reference (Section 4), a Stalnakerian coarse-grained conception of propositional content (Section 5), as well as Evans's account of descriptive reference fixing (Section 6). The discussion is brought to a close by concluding that either true singular existentials are a priori or apriority is not necessary for rational indubitability (Section 7).

中文翻译：

---

存在与可信度

本文认为，真正的单数存在主义在理性上是不容置疑的。在阐明和提出主张后（第 1 节），它针对笛卡尔怀疑论和语义外在论（第 2 节）、弗雷格的命题内容的细粒度概念（第 3 节）、克里普克的指称因果理论（第 2 节4），一个 Stalnakerian 粗粒度的命题内容概念（第 5 节），以及 Evans 对描述性参考固定的说明（第 6 节）。讨论结束时得出的结论是，要么真正的单数存在是先验的，要么先验性对于理性的不可怀疑性不是必需的（第 7 节）。