This dissertation identifies the production of a theory of aesthetic evolution--a belief that the higher faculties of taste and sympathy emerged from the feelings of savages and animals--which resulted from the collaborations between evolutionary science and poetic theory and practice in late eighteenth- and nineteenth-century British writing. Even as the theory enabled authors to naturalize taste, sympathy, and social progress, it also permitted them to interrogate the category of the human and to unfold an immanent critique of the physical and psychic violence that attends modern development. Using Wordsworth's influential definition of poetry not as metered verse but more broadly as the "history or science of feelings," I find attempts to historicize and restore embodied sensibility in a variety of literary and non-literary texts, from Anna Barbauld's anti-slavery verse and William Wordsworth's Lyrical Ballads to Charles Darwin's The Descent of Man, and Selection in Relation to Sex, as well as in a variety of genres, from Erasmus Darwin's scientific poetry, to Charles Darwin's popular voyage narrative, to the most lyrical of Thomas Hardy's novels, Tess of the d'Urbervilles.

In each chapter, I aim to understand not only particular texts but also the century-long investment in poetic practice by major British authors who linked natural and social history in diverse forms of writing. The first chapter explores the intersection between poetic practice, evolutionary theory, and political engagement in the anti-slavery verse of Erasmus Darwin and Anna Barbauld, who attempted in different ways to activate the reader's organs of sympathy--the eye and hand--yet, in Barbauld's case in particular, also acknowledged the limits of sympathy as a form of redress. Chapter Two reads some of Wordsworth's best-known verse from Lyrical Ballads and The Prelude within the context of his engagement with the transmutationist writings of Erasmus Darwin and Georges Louis Leclerc, Comte de Buffon, in order to argue that Wordsworth's proto-evolutionary poetry sought to advance human progress while also registering the costs of development and the threat of regression. Chapter Three argues that Charles Darwin made significant contributions to poetic practice and aesthetic philosophy throughout his career: his Journal of Researches promoted natural science as a discipline that inherits poetry's function of humanizing readers, and his later Descent of Man posited that disinterested feeling and aesthetic judgment are products of evolutionary development. Like other proponents of aesthetic evolution, however, the later Darwin also recognized that modern society degrades, as much as cultivates, human taste and sympathy. The final chapter follows this dialectic of aesthetic evolution into the fiction and poetry of Thomas Hardy. Aesthetic evolution and its immanent critique culminate in Hardy's analysis of civilization's return to savagery and ignorance in Tess of the d'Urbervilles and in his poetic practice, which incorporated scientific knowledge toward the "betterment" of the body and the restoration of sympathetic capacity.