 Still a different way of developing naturalistic constructionist accounts of kinds involves using various formal methods to model such kinds. Among recent work in social ontology, Francesco Guala has distinguished “rules-based” approaches to social institutions from “equilibrium-based” approaches (2016, xxv). The former attempts to understand social structure as emerging from the collective adoption of rules, while the latter sees it as emerging along with various solutions to coordination and cooperation problems. As an example of the former, Searle (1995) influentially argues that we can understand social institutions as brought into being by collective endorsement of rules of the form: