This dissertation studies the history of debates about the possibility and nature of the perfect language, from its inception in Plato's dialogue Cratylus to the revival of "Cratylist" debates in the modernist period. I coin the expression "perfect language project" to account for both philosophical and literary attempts to establish an inherently correct relationship between words and things. I address the perfect language projects of three major modernists—Marcel Proust, James Joyce, and Martin Heidegger—each of whom was inspired by a Cratylist nostalgia for language's potential for rightness. What their three projects have in common, I argue, is a philosophical stance that rejects correspondence theories (in which language is understood as the imitation of things by way of phonetic signs) in favor of phenomenology (in which language is the disclosure of particular things in their singularity or 'thisness'). My introductory chapter proceeds from a close reading of the doctrine of 'right names' in Plato's Cratylus to an intellectual history of the various debates the two competing traditions of Cratylism and Hermogenism have inspired. I address related debates in the Renaissance on the nature of Adamic language, through a study of theories current in Milton's era regarding Adam's act of naming the animals in Genesis 2:19. In Chapter Two, I lay out Proust's critique of typological modes of language (e.g. "it was one of those…") through the emphasis he places on particularity in his treatment of sexual categories. In Chapter 3, I argue that Joyce's experimentations with neologism, while seemingly intended to obscure language, were in fact attempts to render particular objects with the higher degree of precision usually attributed to deictic forms of language. In my fourth chapter, I address Heidegger's controversial claim about the inherent rightness of Greek and German philosophical terms. I call attention to the nationalist impulses behind this claim as well as the problems Heidegger's closet Cratylism poses for his philosophy of language.