According to content externalism, the content of our thought is partly determined by the linguistic environment responsible for it. However, there is growing skepticism about the compatibility of content externalism and self-knowledge. The skeptical position holds that, if content externalism is true, then we cannot know our own thought content because we would not be able to discriminate it from relevant alternative thought contents. This argument rests on the proposition that knowledge requires some type of discriminability. In this paper, I argue that this requirement does not apply to a particular type of demonstrative thoughts, more specifically, that in a typical case where we demonstratively denote an object without taking it as anything, in particular, our second-order judgment about our own thinking, whose content includes this use of a demonstrative, constitutes knowledge without due discriminability.