During the past fifty years, utopian studies solidified a functional definition of utopia in the Marxist tradition, which has encouraged a broad focus on social process rather than on content. In the liberal-humanist tradition, however, utopia is often treated as strictly a matter of form and content, particularly genre. I argue that the key to a functional definition of utopia in the liberal-humanist tradition is the Western tradition of rhetoric. Since its beginnings in ancient culture, rhetoric has been concerned with verbal or symbolic persuasion using values and ideals of the audience. I explain how the utopian impulse is inherent in rhetorical theory from ancient to modern times, including examples from Plato, Cicero, eighteenth-century rhetoricians Hugh Blair and George Campbell, and modern rhetorician Kenneth Burke. I give a rhetorical reading of Mannheim and Bloch and suggest other areas of cross-pollination between rhetoric and utopian studies.