This article details an interpretive, qualitative interview study that explored rationales developed by seven social studies graduate students, all experienced teachers, at a large Midwestern university. Interviews revealed three common themes regarding the influence of the rationale development process. The three themes were: providing structure, connecting purpose and practice, and improving professionalism. The themes demonstrate the complex nature of articulating a sense of purpose, even for experienced teachers. While similar, there were considerable differences in the ways the participants conceptualized their purposes. Untangling these differences has implications for social studies teacher educators interested in integrating rationale development into their work with experienced teachers.