Robert K. Greenleaf published two posthumous essay collections (available at Greenleaf.org). Today scores of colleges and universities include Servant Leadership in their curricula and hundreds of companies embrace Greenleaf's philosophy. As Greenleaf strived to serve through education, he became the leader of a movement. Bass, B. M., and Stogdill, R. M. (1990). "Bass & Stogdill's Handbook of Leadership: Theory, Research, and Managerial Applications" (3rd ed.). New York:Free Press. Frick, Don M. (2004)." Robert K. Greenleaf: A Life of Servant Leadership." San Francisco: Berrett-Koehler Publishers. Greenleaf, R.K. (2003). "The Servant-Leader Within: a Transformative Path" New York: Paulist Press. Greenleaf, R. K. (2002). "Servant Leadership:
Robert K. Greenleaf trusted as servants. To the extent that this principle prevails in the future, the only truly viable institutions will be those that are predominantly servant led" [italics original] Greenleaf (2002) felt strongly that his “best test” should apply to all of our institutions. His “best test,” which he knew would be hard to grade, is stated: Do those served grow as persons? Do they, while being served [italics original], become healthier, wiser, freer, more autonomous, more likely themselves to become servants? And [italics original], what is the effect on the least privileged in society? Will they benefit or at least