This paper examines several aspects of Alexander Wendt's Quantum Mind and Social Science. The paper questions the nature of the task, as ontologies are debated in a scientific field once there is a widely accepted substantive theory that stands in need of interpretation, as with Newtonian physics or quantum mechanics; doing this job for international relations (IR) is highly questionable give that there is no widely accepted substantive theory of IR that needs an interpretation. Second, the paper questions Wendt's view of the consequences for ontology of quantum theory being replaced in the future; Wendt the interpretation of the history of science maintains that in the physical sciences a new theory subsumes the older theory, including its ontology. But, this seems to misread history, while the empirical content of classical physics is subsumed by relativity theory, it is far from true that the former's ontology was subsumed. The ontologies are in sharp contrast. The paper raises questions also about the notion of ‘truth’ and of the meaningfulness of evaluative concepts like ‘justice’.