This chapter explores the psychological principles underlying effective leadership through the concepts of introspection and the “devil’s advocate” approach. It argues that self-awareness and deliberate contrarian thinking enhance decision quality by exposing biases and broadening perspectives. Drawing on research on cognitive diversity and examples from business, science, and politics, this chapter demonstrates how structured dissent fosters innovation and resilience in teams. The accompanying “Vujà de” exercise encourages leaders to challenge habitual routines, critically reassess organizational practices, and cultivate a culture of continuous learning and constructive questioning (Jones, Leadership 2, 2006).