This dissertation analyzes the various strands of essayism in French and Italian fiction from the 1960s to present. Beginning with Montaigne, Chapter 1 defines the essay's main features and surveys important theories of the essay into the twentieth century. Chapter 2 offers an expansive genealogy of European essayistic fiction from the early twentieth century to present. Early essayistic fiction, exemplified by writers such as Valéry, Proust, Musil, Broch, and Pirandello, fell dormant until the late 1960s when writers rediscovered that the essay's tentative nature and its rhetorical structures (digression, dialogism, contingency, hypothetical language) could be enlisted to reorient the novel from a realist trajectory to a more open-ended, speculative, and metaphysical one. These writers include Michel Tournier, Italo Calvino, Claudio Magris, Patrick Chamoiseau, and other contemporary French, Francophone, and Italian novelists. This study posits that the essay and the novel are highly compatible forms that, when interfused, create heretofore unexploited expressive possibilities. The essay's manifold stylistic and thematic freedoms and the novel's provision of a fictional world in which a thought process might be played out create the conditions under which the human imagination and observational and critical aptitude can be exercised to the fullest. Essayism, which involves a reflective "trying out' of the world's possibilities without a specific objective, tends to bleed outside generic borders into other written forms and into extra-literary attitudes and behaviors. The examples in this study evince the ubiquity of essayism in late twentieth-century European fiction.