This paper contributes to the literature on ontology and the history of economic thought by examining the ontological commitments of Nobel Laureate Elinor Ostrom from the vantage point of recent work on social positioning theory (SPT). The comparison highlights important features of Ostrom’s thought on common pool resources (CPRs), most notably her emphasis on social positions and the correlative nature of the rights and duties and the role of power and authority associated with them. In addition to highlighting similarities between Ostrom and SPT, the paper also identifies differences and possible gains from trade. It is argued that Ostrom’s approach could potentially be enhanced by following SPT in allowing for the social positioning of objects as well as people, and that SPT might benefit from Ostrom’s ideas about the epistemic challenges involved in deliberate attempts at social positioning, and the possibility of failures in social positioning such challenges might entail.