The purpose of this article is to explore three behaviorist theories and their roles within the evolving paradigm of nursing. The authors suggest that the behaviorist theories of locus of control, self-efficacy, and the health belief model are derived from deterministic philosophical premises. These premises are in direct conflict with the premise of free will. As interpreted by the authors and many others, the emerging paradigm of nursing relies on the free will of the individual, the ability of the individual to choose for himself/herself what course of action to take, to avoid, or to pursue. The authors address the psychological deterministic philosophical premises within the three theories and utilize nursing theories to compare and contrast the views of free will and determinism. Finally, they suggest that the use of borrowed and applied theories should decline when nurse scientists are true to the philosophical assumptions of theories within nursing science.