Agon: Poetry's Challenge to the Mathematization of Reality narrates the battle for truth-telling authority between poetry and mathematics in the 1920s-1960s. Analysing subversive uses of mathematical metaphors in British and American poetry, it argues that modernism posed the last serious challenge to mathematics, whose authority to determine for all the true nature of reality had grown steadily from Newton to Einstein. The book paints William Blake's defiance of the Enlightenment as the background or emblem to the modernist resistance, whose main protagonists were William Empson, Laura Riding, Charles Olson, W.B. Yeats, and Michael Roberts, among others. Introducing a novel paradigm of criticism -- the agon -- to interdisciplinary study in the humanities, Anirudh Sridhar traces the rise of mathematics from the seventeenth century onwards, and shows how it supplanted philosophy, poetry, and the other arts as the language in which reality would be described and comprehended. He explores (from the agonistic paradigm) the role of calculus, quaternions, Riemannian manifolds, non-Euclidean geometry, analysis, mathematical logic, and more. Extensive close readings of mathematical poems show how they critique the ways in which mathematical tools reduce phenomena and abstract the world of experience. These readings bring out the formal, performative, and reflexive ways in which such poems act as defences of poetry's ability to achieve fidelity to experience and a richer picture of reality. Rather than posing poetry as a passive receptacle of mathematical ideas, the agon allows for an intense contestation of poetic and mathematical modes and their claims to truth through careful attention to the playfulness and subversiveness animating cross-disciplinary interaction.