How do skeptics "know"? — A explanation based on two theories of knowledge representation: Dual-representation view of knowledge

The skepticism in the field of epistemology has never lacked advocates and attackers. In order to defend skepticism and answer the question of how skeptics can have knowledge, this paper first constructs a enhanced  version of the "Brain-in-a-Vat" modelto defend skepticism, and analyzes it to argue that the sensitivity principle,  security principle, and contextualism of knowledge cannot completely dismiss the challenge from the enhanced version of the "Brain-in-a-Vat" model of skepticism. But this does not mean that skeptics cannot have knowledge. By constructing the paradoxical propositions P1: I don't know that the skeptic's hypothesis is wrong; and P2: I have perceptual knowledge of the external world, a new solution is proposed from the perspective of knowledge representation: a representation theory of knowledge about mental states is held when adhering to proposition P1, and a representation theory of knowledge about symbolism is held when adhering to proposition P2. These two representational theories succeed in explaining how skeptics can “know” while maintaining skeptical intuitions.