A general trend in recent philosophical and empirical work aims to undermine various traditional claims regarding the distinctive nature of self-knowledge. So far, however, this work has not seriously threatened the Cartesian claim that (at least some) self-knowledge is immune to the sort of sceptical problem that seems to afflict our knowledge of the external world. In this paper I carry this trend further by arguing that the Cartesian claim is false. This is done by showing that a familiar sceptical argument that targets my knowledge of the external world can be adapted to target my belief that I exist, along with any of my self-knowledge that I know entails my own existence. Thus, my self-knowledge and my knowledge of the external world are subject to the same sort of sceptical problem.

最近哲学和实证研究的普遍趋势旨在破坏关于自我知识的独特性的各种传统主张。然而，到目前为止，这项工作并没有严重威胁笛卡尔的主张，即（至少部分）自我知识不受那种似乎影响我们对外部世界的知识的怀疑论问题的影响。在本文中，我通过论证笛卡尔的主张是错误的来进一步推动这一趋势。这是通过表明以我对外部世界的知识为目标的熟悉的怀疑论证可以适应我对我存在的信念，以及我知道的任何自我知识导致我自己的存在。因此，我的自我认识和我对外部世界的认识都面临着同样的怀疑问题。