Dissociation is a rhetorical device in which the speaker separates a notion considered by the audience to form a unitary concept into two new notions.^[1]

Kathryn Olson, Director of the Rhetorical Leadership Program at the University of Wisconsin-Milwaukee, explains that by doing this, the speaker fundamentally changes the reality of the thought system in question by creating a disjunction between what was an integrated concept to begin with.^[2] According to M.A. van Rees, dissociation is a two step process of distinction and definition: distinction divides a single concept into two new notions for the audience and definition replaces the original term or concept with two new terms, each with their own definitions.^[1]

This process is rhetorically effective when a rhetor presents a particular concept in a light that is favorable to his/her interests by dissociating a term with any notions that do not serve the rhetor's purpose.^[1] According to Øyvind Ihlen, the rhetor attempts to "remove an incompatibility that arises from confrontation between propositions" to better affect an audience's beliefs.^[3] Defining a situation through dissociation, when done correctly, authoritatively declares the two resulting concepts distinct and rules out any further argument.^[1]