The article argues that all disciplines examining human thought could use certain shared analytical categories. This would not mean eradicating all differences between various approaches such as intellectual history and discourse analysis, but acknowledging that they are examining partly the same basic entities. The article argues that ideational entities in human thought could be understood as concepts, beliefs, and their constellations. The article discusses the views of scholars who have theorized similar categories and shows how these can be studied through historical language use. Shared analytical categories would enhance interdisciplinary dialogue between scholars of human thought and allow more rigorous debates on issues that truly divide different disciplines, such as the explanatory values of human agency and structures.