This paper focuses on the notion of the diagram and, more precisely, on diagrammatic images, whether they are produced in the sciences or in the arts. I will examine Charles Sanders Peirce, Gilles Deleuze and Nelson Goodman perspectives of the notion of diagram, in order to identify the constitutive characteristics of this notion. Among these constitutive features, my objective is to describe the gesture, in its diferent declinations: the gesture of reasoning and that of artistic production.