Since its early history in Greek culture, traditional rhetorical study has focused primarily on persuasive language used in the public sphere. There has been little study, however, of what Jean Nienkamp calls internal rhetoric, which "occurs between one aspect of the self and another" inside one's mind. Nienkamp opens the study of internal rhetoric by discussing how the concept developed alongside traditional classical and modern rhetorical theory. Nienkamp shows how we talk to ourselves, or more specifically, how we talk ourselves into things: justifications, actions, opinions, theories. She explains that just because we see ourselves as divided, as torn in different directions by conflicting desires, duties, and social mores, it does not mean that we are split into discrete identities that neither interrelate nor interact. In this groundbreaking study, Nienkamp identifies two major aspects of internal rhetoric: "the conscious 'art' of cultivated internal rhetoric" and "the unconscious 'nature' of primary internal rhetoric."
Selecting a small number of figures from the history of rhetoric - including Isocrates, Plato, Aristotle, Francis Bacon, Lord Shaftesbury, Richard Whately, Kenneth Burke, Chaim Perelman and Lucie Olbrechts-Tyteca, George Herbert Mead, and Lev Vygotsky - Nienkamp argues for a "version of the rhetorical self that takes into account both the ways we are formed by and formulate internal and external rhetorics and the ways our physical bodies act as a contributing scene - an agora - for internal rhetoric.