The history of ideas is most prominently understood as a highly specialized group of methods for the study of abstract ideas, with both diachronic and synchronic aspects. While theorizing the field has focused on the methods of study, defining the object of study – ideas – has been neglected. But the development of the theories behind material culture studies poses a sharp challenge to these narrow approaches. It both challenges the integrity of the notion of abstract ideas and also offers possibilities for enlarging the scope of the ways in which we can study ideas historically. It is proposed here to regard ideas as mental relations deeply connected to human communication by both thinking and doing. This connection of ideational thought to human production and behavior is a deep foundation for the history of ideas as an interdisciplinary historiographic means of understanding moral life.