Stephen Covey (The Author)
As the author of this book, Covey interposes himself and his own experiences into the prose. His expertise and thorough grounding in psychology are assets in his clear explication of the problems with the personality ethic and his solution in the quest for regaining the character ethic: the Seven Habits. Covey includes many personal experiences that aptly illustrate his points, and he thus appears to be the most prominent character in this nonfiction work.
Sandra
Sandra, Covey's wife, is a common character in his personal illustrations. Aside from being his partner in marriage, she is a character in many dialogues, especially concerning their children. Covey's talks with Sandra are some of the most important events in his life that make him realize the harsh dichotomy between the character ethic and the personality ethic, as well as their unwitting subscription to the latter with regard to familial relationships.
Covey's Children
Covey often uses his children as examples from his personal life as well. He uses the example of his son to describe the subconscious effects of the personality ethic both on his son's social situation and on their attempts to bring him out of his awkward stage. Covey's daughter appears in several examples as well, playing a selfish little girl or a Star Wars-loving teenager. In every scene, the adorable antics of these children help illustrate Covey's point in a memorable fashion.
Nicolaus Copernicus
Copernicus was a Polish astronomer and mathematician during the Renaissance. After careful study and calculation, he determined that the solar system actually revolves around the sun (heliocentricism), rather than around the earth (geocentricism), as had traditionally been believed. This shift of perspective is an example of what Covey calls a Paradigm Shift, which is a change of frame of reference that allows a person to see something in an entirely different light.
Albert Einstein
Einstein's Theory of Relativity, expanding on and altering the perspectives of Newton, created another Paradigm Shift. What Newton had believed to be fixed were in fact relative, alterable by forces beyond their scope. Covey uses this anecdote as yet another example of a Paradigm Shift occurring in history, demonstrating its nature and effectiveness.