The book includes over 30 years of subsequent research into the psychological and social factors which result in immoral acts being committed by otherwise moral people.

The title takes its name from the biblical story of the favored angel of God, Lucifer, his fall from grace, and his assumption of the role of Satan, the embodiment of evil.

[4] The first chapter is on the book's title theme of Lucifer and on the nature of moral transformation as an outcome of the interplay between individual disposition, situation, and systems of power.

[6] Zimbardo relates his experience as an expert witness for the defense at Frederick's military trial, and describes his view of what led to an "All-American poster soldier" becoming involved in the torture of prisoners.

The final chapter describes the concept of heroism, the key roles of Joe Darby, the whistleblower of the Abu Ghraib events, and Christina Maslach, the graduate student who convinced Zimbardo to end the Stanford experiment early, and advice on how to resist negative situations.