The flourishing of the essay as a protean literary form in an age marked by growing interest in essaying systematic knowledge reflects a tension within eighteenth-century empiricism. Two divergent subgenres emerged from this tension. The conversational essay, first, drew upon a Montaignian tradition rooted in scepticism, dialogue, and performative rationality; these essays were associated with a form of pragmatic empiricism at ease with the idea of human knowledge as intersubjectively constituted in the public domain. On the other hand, the systematic essays of the Enlightenment, spurred on by John Locke’s attempt to establish ‘order’ in intellectual inquiry, deployed the essay as an instrument for establishing Universal Truth and what Leibniz termed ‘demonstrative knowledge’. In considering the epistemology of the eighteenth-century essay in Britain, this chapter explores not only how this bifurcated empiricism influenced the development of the essay, but also the ways in which the essay reconstituted empiricism itself.