Nursing's ways of knowing and dual process theories of cognition.

Aim: This paper is a comparison of nursing's patterns of knowing with the systems identified by cognitive science, and evaluates claims about the equal-status relation between scientific and non-scientific knowledge.
Background: Ever since Carper's seminal paper in 1978, it has been taken for granted in the nursing literature that there are ways of knowing, or patterns of knowing, that are not scientific. This idea has recently been used to argue that the concept of evidence, typically associated with evidence-based practice, is inappropriately restricted because it is identified exclusively with scientific research.
Method: The paper reviews literature in psychology which appears to draw a comparable distinction between rule-based, analytical cognitive processes and other forms of cognitive processing which are unconscious, holistic and intuitive.
Findings: There is a convincing parallel between the 'patterns of knowing' distinction in nursing and the 'cognitive processing' distinction in psychology. However, there is an important difference in the way the relation between different forms of knowing (or cognitive processing) is depicted. In nursing, it is argued that the different patterns of knowing have equal status and weight. In cognitive science, it is suggested that the rule-based, analytical form of cognition has a supervisory and corrective function with respect to the other forms.
Conclusions: Scientific reasoning and evidence-based knowledge have epistemological priority over the other forms of nursing knowledge. The implications of this claim for healthcare practice are briefly indicated.