In Aquinas’s Commentary on the Psalms, the tongue plays a diverse and symbolic role. It is both part of the human person and that which mediates the person to the world. It is a weapon used to revile enemies, flattering and deceitful, a means of sin, and an almost untamable source of temptation. Here, Aquinas’s teaching on the tongue interfaces with his well-known virtue ethics. Yet, the tongue is also the instrument for the praise of God, both spoken and sung, and that through which the Holy Spirit speaks in Biblical inspiration. The tongue as the seat of the sense of taste becomes a metaphorical image for experience of the divine goodness. Closely tied to the rationality of human language, the flexibility of the human tongue expresses the contradictions and possibilities of the human condition.