Throughout her career, Anne-Marie Christin has been particularly interested in the history of writing, from its emergence in Mesopotamia and Egypt to the contemporary era when new writing practices are appearing. She has thus examined the complex relationship between writing and image and language, between what is seen and what is heard. Our alphabetic culture has often brought these two fundamentally heterogeneous domains together by subjecting them both to the model of the 'line'. The text that arranges the letters of the alphabet in a line would correspond to the equally linear sequence of sounds in a speech. Anne-Marie shows, in her book L'invention de la figure, that such a conception is far from accounting for the nature and all the potentialities of writing. It is to this analysis of the very particular way in which the line is conceived by Anne-Marie Christin that this article is devoted.