The constitutive idea centres on the proposition that, as a matter of social fact, law and wider social life each make up and, over time, dynamically shape, the other. This paper argues that we can draw upon designerly ways to make that the constitutive idea more available to scholars, as well as to the wider world. It first highlights the empirical, conceptual and normative dimensions of the constitutive idea. Next it introduces designerly ways, and some examples of how they have already been used at the intersections of legal and economic life. Finally, it identifies three specific problems (one empirical, one conceptual and one normative) arising out of scholarship that attends to the constitutive idea, and explains how we might adapt existing designerly practices to address them.