This paper explores the synesthesia between eye and tongue, the senses of taste and sight – the lowest and the highest senses according to the traditional hierarchy of the senses. Today this relationship immediately brings to mind gastronomical aesthetics – think of the popularity enjoyed by culinary photography or the aesthetically sophisticated dishes prepared by top restaurants – but the forms of reciprocity between taste and sight go beyond mere aesthetics. For centuries, cooks have been especially attentive to the visual presentation of food, as evidenced in paintings, engravings, and ancient recipe books. A beautifully presented dish catches the eye and stimulates the desire to eat it. Sight can thus be considered to be foretaste, a promise of what will be savored, or – when considering the possible risks of ingestion, such as sin or disease – as a restraint. But while one can taste with the eye, one cannot exhibit the organ that tastes it. The tongue stays hidden between the lips, concealed behind the teeth. It resists representation, and when it is represented, it is most always associated with a logic of excess, or of disorder. In this sense, the tongue is the mark of transgression: talking with your mouth full is regarded as impolite; in extremes cases, an open mouth can be seen as a sign of stupidity, even madness. My paper examines this relationship between interiority and exteriority by drawing on textual and iconographic resources, exploring treatises of the senses, books of manners, physiognomic works, as well as images related to the sin of gluttony.