Grammatology is a term introduced by Jacques Derrida to denote his general theory of writing. Although, using the word theory is inappropriate in this context Derrida himself is using it. He does it, as one of his main goals is to demonstrate that theory or science of writing is impossible to exist.
The goal of what Derrida calls grammatology is to replace the common theory of signs and to overcome the metaphysics of what is available. It is accepted that speech was first to develop, and writing – was second.
Graphic signs are based on phonetic signs.