Objective: Contribute to situate and characterize the knowledge in nursing. Methodology: Original theoretical reflection. Development: The notion of nursing as an ecology of knowledge calls for a clarification of the status of science that we assign to it. Nursing affirms itself as science in a context of paradigmatic transition, which, on the one hand, creates some difficulties, but, on the other hand, opens a wide range of opportunities. Nursing is action knowledge expressed in professionalized integral care, thus it is a practical human science. It is a science of plural knowledge. Conclusion: The specific knowledge of nursing results from a process situated in a given context, where, in a process of reflection in action in a hermeneutic spiral, scientific knowledge intersects with other experiential knowledge. A mix of knowledge that corresponds to the various patterns. These patterns coexist and interact with each other and the context, which turns nursing knowledge into a true ecology of knowledge. The systematization of nursing knowledge will be truly promising in the light of an epistemological pragmatism and an understanding of the operations of systematization that allow moving from personal knowledge to public knowledge. Public knowledge is systematized and validated to become scientific knowledge.