This paper problematizes the concept of pedagogical content knowledge by giving an account of its guiding principles, critiquing its underlying assumptions, and providing a sketch of potential resolutions to possible contradictions. The view of subject matter (and the idea of transforming subject matter for teaching) offered by Shulman works well for simplified understandings of learning and teaching (where the teacher deconstructs disciplinary knowledge while the student constructs meaning); however, falls short with somewhat dynamic (where knowledge is considered more as a process than as an object) and complex views on knowing and learning (as it is often non-linear or unpredictable).