All learned occupations have a definition of professionalism, a code of conduct. It is where they spell out their ideals and duties. The codes are sometimes stated, sometimes just understood. But they all have at least three common elements.
First is the expectation of selflessness: that we who accept responsibility for others─whether we are doctors, lawyers, teachers, public authorities, soldiers, or pilots─will place the needs and concerns of those who depend on us above our own. Second is an expectation of skill: that we will aim for excellence in our knowledge and expertise. Third is an expectation of trustworthiness: that we will be responsible in our personal behavior toward our charges.
Aviators, however, add a fourth expectation, discipline: discipline in following prudent procedure and in functioning with others.
from The Checklist Manifesto, p 182