"S" come serpente, come snake, come Schlage ... Warburg, Kallir e Merleau-Ponty

The article is divided into two parts. In the first, starting from Kallir’s analyses of the psychogenetic source of the alphabet we show how the sign “S” has a semantic field that within Indo-European languages designates with exceptional frequency slithering movement and hissing sound. In the second part, the reflection is enlarged by addressing the problem of the arbitrary relationship between sound and graphic sign within alphabetic culture.