Nursing has traditionally been practiced and taught with the characteristics of a natural science, which guided nursing research, just as the natural sciences have preferably sought to quantify and specify cause-effect relationships; to explain, predict or control the phenomena that professional practice must face. Thus, a point has been reached in which tasks, technology and perhaps education have been the predominant frames of reference to face professional tasks. In the era of modern nursing, the challenge arises of changing a practice based exclusively on technical knowledge or a biological vision, to a practice that is reflective and transformative of the health realities of populations. This implies looking at realities with the approach of inductive naturalism or phenomenology. Here reference is being made to the existence of two paradigms that guide nursing; the paradigm of empirical positivism or the totality of man-environment and the paradigm of inductive naturalism of simultaneity of man-environment.