Twentieth-century critics have opposed the supposed objectivity of the essay to the letter and diary as private, self-expressive, and autobiographical genres. But this was a modern development. From Michel de Montaigne to the early nineteenth century, the essay, the letter, and the diary were more alike and far more closely aligned than they later became, particularly with regard to representations of the self and notions of publicity. For instance, they were all considered forms of address, and means of presenting one’s intellectual physiognomy to others that were likely to be read aloud, shared, and discussed. This chapter therefore explores now-forgotten family resemblances among these genres both in form and function and concludes by showing where they were fused or embedded in one another.