Nursing is a profession within the health care sector focused on the care of individuals, families, and communities so they may attain, maintain, or recover optimal health and quality of life. Nurses may be differentiated from other health care providers by their approach to patient care, training, and scope of practice. Nurses practice in many specialties with differing levels of prescription authority. Many nurses provide care within the ordering scope of physicians, and this traditional role has shaped the public image of nurses as care providers. However, nurse practitioners are permitted by most jurisdictions to practice independently in a variety of settings. In the postwar period, nurse education has undergone a process of diversification towards advanced and specialized credentials, and many of the traditional regulations and provider roles are changing.
The men in the laboratory... cannot be said to observe the actual objects of their curiosity at all. ...The sense data on which the propositions of modern science rest are, for the most part, little photographic spots and blurs, or inky curved lines on paper. ... What is directly observable is only a sign of the "physical fact"; it requires interpretation to yield scientific propositions.
Susanne Langer, Philosophy in a New Key (1942)
Within the short span of a human life and with man's limited powers of memory, any stock of knowledge worthy of the name is unattainable except by the greatest mental economy. Science itself, therefore, may be regarded as a minimal problem, consisting of the completest possible presentment of facts with the least possible expenditure of thought.
Ernst Mach, The Science of Mechanics: A Critical and Historical Account of Its Development (1893) p. 490, Tr. Thomas J. McCormack.