Simon Sinek (born 1973) is a contemporary author and speaker whose work focuses on leadership, motivation, and purpose. He is best known for the concept of Why, which holds that enduring individuals and organizations are defined not primarily by what they do or how they do it, but by the deeper reason that drives their actions. In books such as Start With Why and Leaders Eat Last, Sinek develops a framework centered on moral coherence, trust, and collective responsibility. His thinking emphasizes the importance of shared meaning, organizational culture, and leading by example, presenting leadership as an ethical commitment rather than a mere exercise of authority.