From Scepticism to Platonism

Abstract

Abstract A philosophical concept of signs first turns up in Augustine's early writings as part of a Hellenistic epistemological debate reported by Cicero, an advocate of the scepticism of the Academics. The Academics argue that no sensible appearance can serve as a sure criterion of truth because it may always have the same kind of ambiguity as a “common sign.” Augustine thinks that behind this scepticism hides Platonism, which undermines any claims to knowledge based on the senses. Whereas the “horizontal” similarity of sensible things to one another undermines all claims to empirical knowledge, Platonism recognizes a “vertical” similarity, the resemblance of sensible, “truthlike” things to intelligible truth found in a higher, unchanging realm where certainty is possible. Augustine later invents a new Platonist semiotics, in which sensible things may not only resemble but also signify intelligible things.