Research has elevated the proposition of knowledge's domain specificity from a working hypothesis to a de facto truth. The assumption of domain specificity structures handbooks, organizes branches of funding agencies, and provides headings for conference proceedings. Leading researchers often focus on a single slice of the school day despite the possibility that such segments swirl into a blur for children. The authors examine the domain-specific landscape, beginning with the recent past, when domain generality, not domain specificity, reigned supreme. They then examine the transition to domain-specific approaches. Next, they offer an alternative to both positions, a stance they call the "comparative understanding of school subjects." A comparative understanding trains attention on how the same children understand multiple subjects in the curriculum. The authors argue that this approach represents a promising path for conceptualizing research on children, schooling, and thinking by raising new questions about children's understandings. (Contains 12 notes.)