This paper aims at introducing Complexity, by showing its importance through research carried out in the Nursing area. It consists of a reflection divided into two parts: the Complexity's principles, by Edgar Morin; and research on Nursing originating from Complexity. By taking into account the Complexity involving the objects of study in Nursing, it is desirable to choose a methodological path which is more appropriate to its comprehension, that is, to choose only one method which is more likely to portray a real picture of the subject. By understanding such method as a path to investigation combined with and originating from theory and not as a support to scientific practice, the concept of Complexity, by Edgar Morin, when used as a theoretical choice, ends up as a guide to a methodological path.
nursing; research; nursing philosophy