This chapter explores the relationship of the adult essay with the ‘theme’, which was the name for school-essays until the mid-nineteenth century. Themes were, mostly, short prose pieces, focused on a moral subject which was also called a theme, written almost exclusively in Latin until English themes began to emerge in the late eighteenth century. The chapter argues that in the nineteenth century, the modern pedagogical essay emerged out of the Erasmian theme, combining many of its structures with the Baconian essay’s priority on individual experience and ideas. Meanwhile, the Romantic essayists, Charles Lamb and Thomas De Quincey, chief among them, created the modern literary essay by carrying forward the priority the theme assigned to rhetoric over experience, while on the other hand imitating Montaigne’s play with the oratorical structures of the theme, and with its subject (also called a ‘theme’).