Publisher Summary Cognitive dissonance occurs when a cognition that a person holds follows from the obverse of another. This chapter examines those relationships and proposes a new definition of cognitive dissonance. The state of the empirical findings to move toward a more comprehensive view of dissonance is reviewed in the chapter. When one understands what produces dissonance, it still needs further elaboration of the process to understand adequately the cognitive changes that ensue. The concept of dissonance must be differentiated into the concepts of dissonance arousal and dissonance motivation. It leads to the cognitive changes that are generally associated with cognitive dissonance. The integrative review of dissonance research is provided in the chapter. This survey narrows the scope of the theory, because it identifies the limited conditions under which dissonance effects are most likely to arise; cognitive dissonance is not the product of opposing cognitions. Dissonance theory concepts are applied to a broad range of phenomena so that the formulation remains exceedingly important.