Florence Nightingale created or started many of the nursing theories that became properly accepted medicine in later years. One of her major theories was the idea that nursing itself was a separate field from "medicine" or "doctoring," in that nursing is more about the facilitation of medical care than about the medical care itself. Nurses, in her eyes, should be informed and educated about the care of patients, but should focus their attentions making treatment easy, beneficial, and available. She also believed that nursing was a care-giving philosophy first, and that it could be performed by anyone; however, she strove for better education and training for nursing students so they could properly help both patients and doctors.
Perhaps her most important theory was that of environmental nursing; Nightingale believed that nursing "is an act of utilizing the environment of the patient to assist him in his recovery" (Nightingale 1860/1969) (Wikipedia). In other words, the environment of the patient is as important as the care given by doctors and nurses; if the patient is in an environment that exacerbates the condition -- such as mold or low temperatures -- the care given will not be as effective. Today, nurses strive to make sure their patients have an environment that allows fast and easy treatment. Technologies such as blood-pressure monitoring allow the nurse to quickly understand patient discomfort, and then treat it or inform a doctor. In this manner, nurses still use their environment to help them care for patients, instead of simply acting on the patient alone.