This essay approaches Jubilate Agno (1758-1763) as constitutive of an "emotional practice" of enthusiasm. Using affect and practice theories, I argue for increased attention to the modulation of feeling made manifest in Jubilate Agno , which realizes Smart's religious, reparative, and creative impulses. The enthusiastic posture and practice of the poem afford Smart, if not always divine inspiration and freedom, at least sustaining resolve during his years of anguished confinement for "madness." That such a posture and practice are so often sublime, as expounded by Robert Lowth, reveals the radical possibilities of a pliable writing process.