Proceedings of the Annual Meeting of the Cognitive Science Society

This paper derives a number of logically necessary principles that govern cognitive functioning, and reviews empirical evidence supporting the validity of these principles. It advances an argument in which mental representations are conceived as indexical signs, in that they are causally related to the objects they represent. This indexicality gives rise to four general principles of cognitive functioning. First, mental activity is strongly influenced by that which is present. Second, mental activity exhibits relative insensitivity to absence. Third, minds exhibit difficulty representing negation, because representing negation entails representing the absence of that which is negated. Fourth, thinking is believing, in that representing a proposition implicitly entails accepting the truth of the proposition.