Despite a rapidly changing world, leadership remains crucially important in institutions ranging from schools to nations. Much of what is beneficent in the world has been inspired by farsighted leaders, even as many of the horrors of the world have been wrought by leaders who, while perhaps equally gifted, have used their powers destructively. This study helps explain what leadership entails, from a psychological perspective, and why skilled, constructive leadership has not proved easy to come by in closing the years of the twentieth century. The final pages contain suggestions about how effective leadership might be fostered in the future. The text presents, in 3 parts, 11 examples of leadership. Part 1, "A Framework for Leadership," is divided into 3 sections: "Introduction: A Cognitive Approach to Leadership"; "Human Development and Leadership"; and "The Leaders' Stories." Part 2 includes 9 of the 11 case studies of the 20th century leaders: "Margaret Mead: An Observer of Diverse Cultures Educates Her Own"; "J. Robert Oppenheimer: The Teaching of Physics, the Lessons of Politics"; "Robert Maynard Hutchins: Bringing 'The Higher Learning' to America"; "Alfred P. Sloan, Jr.: The Business of America"; "George C. Marshall: The Embodiment of the Good Soldier"; "Pope John XXII: Rediscovering the Spirit of the Church"; "Eleanor Roosevelt: Ordinariness and Extraordinariness"; "Martin Luther King, Jr.: Leading in a Rapidly Changing Environment"; "Margaret Thatcher: A Clear Sense of Identity" and finishes with "A Generation of World Leaders." Part 3, "Conclusion: Leadership That Looks Forward," includes the final case studies, "Jean Monnet and Mahatma Gandhi: Leadership beyond National Boundaries," and a summary, "Lessons from the Past, Implications for the Future." Appendices include: (1) "The Eleven Leaders Viewed along the Principal Dimensions of Leadership" and (2) "The Leaders of the Second World War." (Includes a name index, a subject index, and approximately 375 references.) (AA)