This article examines the philosophical stakes of Eliza Haywood's confrontation with a topical economic crisis: the South Sea Bubble of 1720. In Memoirs of a Certain Island (1725), Haywood recalibrates her theory of erotic desire to the conditions of the market. Her project intersects in two ways with John Locke's arguments in An Essay Concerning Human Understanding (1690–94). First, Haywood follows Locke in using the category of desire to relate personal experience to social formation. In her hands, desire accounts for speculative investment as well as erotic coupling. Second, Haywood shows that the desire licensed by modern finance threatens the "self-consciousness" that, for Locke, defines personal identity. Desire works differently in Memoirs of a Certain Island than it does in Haywood's more familiar writings, such as Fantomina (1725). Rather than promoting self-consistency, speculative desire disorders the minds of people that it actuates. Haywood articulates the solution, as well as the problem, through the idiom of sexual passion. Her vision for recovery depends on the salutary potential of another species of erotic attachment, passionate love.