SummaryUnder the assumption of the materialistic‐mechanistic ontology implicit in classical physics, quantum theory as interpreted through Niels Bohr's epistemology of complementarity is not formally objective; i. e., it is not informative of the state of physical systems independent of particular phenomenal manifestations of them. However, an analysis of the notion of the “physical system”, in theory, as experienced, and as existing “in‐itself”, reveals that if the older ontology is replaced, quantum mechanics through complementarity becomes formally objective, points the way toward a new ontology based on the notion of the power to structure interaction between systems, and provides new insights into the relations between theory, observation, and the na