Our theories of communication have assumed that we deliberate before we express our thoughts; this chapter points out that we implicitly and explicitly hold a rationalist view of thinking and behavior. Instead, social intuition theory proposes that intuition plays a major role in how and what we communicate. This chapter develops the argument for social intuition theory and discusses a range of empirical evidence supporting the theory. It lays out some important ways in which social intuition theory applies to communication theory, for instance, in its explanation of the place and function of giving reasons. It raises questions for communication theory that have gone unattended, and it supplies answers. It discusses how our ideologies take part in our everyday communication behaviors while remaining outside of consciousness. It questions the absence of intuition in textbooks on communication theory.