Abstract
Closed systems are mental artefacts whose structure can neither be explained in terms of innate dispositions nor in terms of the mechanism of natural selection and which stands in contradiction to the conditions of the possibility of information transfer. Kant takes the formal structure of pure mathematics as a guarantor for his reconstruction of a closed system of the subject's structures of knowledge a priori, thereby giving rise to the problem of a normative interface between interior system and exterior information – a problem which is, in this form, not to be solved. By tracing the structure of generative grammar and formal logics back to innate modules, respectively, Chomsky and Fodor are creating the same interface problem, whose basic structure has not yet received the necessary attention