Types of knowledge, theory and research needed in a practice-oriented discipline are considered in relation to different "aspects of reality." Major changes in nursing epistemology are reviewed to show an expanding model of inquiry. It is argued that a paradigm which recognizes a spectrum of reality from "body" through "mind" to "spirit" provides a philosophical basis for understanding the necessity of multiple modes of inquiry and multiple types of knowledge and theory. From this perspective, fundamentally different modes of inquiry are seen as complementary rather than competitive or inherently superior or inferior.
John A. Wolfer (1993) studied this question.