Despite growing emphasis on learning to argue and arguing to learn as educational outcomes in the secondary curriculum, a gap remains between these curricular goals and teachers' practices. The present study seeks to understand this gap by surveying 158 pre-service teachers about their knowledge, beliefs and predispositions related to argumentation and learning. Results reveal a strong, unanimous value for argumentation among pre-service teachers, combined with a vague understanding of what it means to learn and teach argumentation within their academic disciplines. In addition, we found a contradiction between pre-service teachers' belief in the importance of learning to argue and their reluctance to use instructional time to teach it. Finally, we did not find differences in pre-service teachers' perceptions across majors. We conclude with recommendations for fostering pedagogical content knowledge in argumentation to pre-service teachers, particularly in content-area methods classes.