Dr. M. Scott Peck (1983) refers to evil people as...

"Dr. M. Scott Peck (1983) refers to evil people as the “people of the lie”: They are constantly engaged in self-deception and the deception of others. He goes on to say that “the lie is designed not so much to deceive others as to deceive themselves. They cannot or will not tolerate the pain of self-reproach. The decorum with which they lead their lives is maintained as a mirror in which they can see themselves reflected righteously” (Peck, pp. 66–75). Peck observed that although it might be difficult to define evil people by the illegality of their actions, we can define them by the “consistency of their sins” (p. 71)."

Eric W. Hickey. “Serial Murderers & Their Victims” - Fifth Edition. Alliant International University; Wadsworth, Cengage Learning. 2010. (pg. 48)