When a person encounters a persuasive appeal, a salient perception of the message is often the extent to which it is relatively proattitudinal or counterattitudinal. Some studies suggest that counterattitudinal communications are processed more deeply than proattitudinal messages. However, other research has found the opposite processing relation. Similarly, various properties of premessage attitudes and attributes of message sources have been shown to affect message processing. Yet, in some cases, these findings have appeared inconsistent with one another. We suggest that this variety of findings can be organized and understood by considering the motivational states that guide processing of agreeable and disagreeable information, respectively. When encountering counterattitudinal advocacies, people should often be motivated to defend their views, and variables that influence defense motives should determine the amount of processing. Conversely, proattitudinal information presents an opportunity to bolster the premessage attitude. Thus, variables that affect the degree of bolstering motivation can affect the amount of proattitudinal message processing. In this chapter, we present the Discrepancy Motives Model—an integrative framework for organizing how persuasion variables interact with message position to affect the depth of information processing. In addition to processing differences, we discuss implications that this new account holds for understanding other attitude change phenomena.