This book reconstructs the theory of signification implicit in Aristotle’s De Interpretatione and its psychological background in his writing De Anima, a project often envisioned by scholars but never systematically undertaken. I begin by explaining what sort of phonetic material, according to Aristotle, can be a significans and a phônê. To that end, I provide a physiological account of which animal sounds count as phônê, as well as a psychological evaluation of the cognitive content of the phônai under consideration in De Interpretatione: names, verbs, and assertive sentences. I then turn to noêmata, which, for Aristotle, are the psychological reference and significata of names, verbs and assertive sentences. I explain what, for Aristotle, are the logical properties a significatum must have in order to be signified by the phonetic material of a name, verb or assertive sentence, and why noêmata can fulfil those logical conditions. Finally, I elucidate the |