Through careful and imaginative readings of various scientific texts, the philosophy of Immanuel Kant and Longinus, and the works of such writers as William Blake, Percy Bysshe Shelley, Mary Wollstonecraft, and Lord Byron, Sha explores the influence of contemporary aesthetics and biology on literary Romanticism. Revealing that ideas of sexuality during the Romantic era were much more fluid and undecided than they are often characterized in the existing scholarship, Sha’s innovative study complicates received claims concerning the shift from perversity to perversion in the nineteenth century. He observes that the questions of perversity—or purposelessness—became simultaneously critical in Kantian aesthetics, biological functionalism, and Romantic ideas of private and public sexuality. The Romantics, then, sought to reconceptualize sexual pleasure as deriving from mutuality rather than from the biological purpose of reproduction. At the nexus of Kantian aesthetics, literary analysis, and the history of medicine, makes an important contribution to the study of sexuality in the long eighteenth century.