The inferential and equational models from ancient times to the postmodern

To put the notion of the sign at the centre of philosophical development and consider it basic to a post-modern development of thought is the basic idea which makes John Deely’s Four Ages of Understanding an innovative one. But a full awareness of this notion can be traced way back to the beginnings of the fifth century AD, in the works of Augustine, where the two different theories of signs present in the Greek period - the semantic theory of the linguistic sign (following an ‘equational’ model) and the logical-epistemological theory of non-linguistic signs (following an ‘inferential’ model) - are amalgamated. The aim of this paper is to show that Augustine makes a move which is both symmetrical and a mirror image of what Saussure does: the latter unites the two theories and two classes of sign, setting up the linguistic sign as the guiding principle while Augustine subsumes all types of sign within the class of non-linguistic signs. But it is the Augustine’s move that opens, as also Deely says, a link with the post-modern era, proposing a semiotic model that is homogeneus with that of Peirce.