In this paper I try to establish the relevance of Peirce's Semeiotics to the conceptual foundations of Cognitive Science. Given Cognitive Science's commitment to the Representational Theory of Mind, I try to clarify the nature of mental representation from the standpoint of Peirce's general theory of signs. As it turns out, mental representations, because of their special role as interpretants of non-mental signs, present especial problems for their interpretation, whose solution Peirce anticipated in a way very close to that developed (...) in Cognitive Science. (shrink)