This paper describes the Tri-Partite Theory of institutional change, which proposes that organizations in general and educational institutions in particular pass through three phases, each dominated by a specific personality type: person-orientation (loyalty to a charismatic leader as the basis of motivation); plan-orientation (functions controlled by a planner, supported by members); and position-orientation (bureaucratic ossification and loss of purpose). Each of these phases of orientation, and the personality types that dominate them, are described in detail, along with examples from a wide range of historical, organizational, and educational contexts. Included is a discussion of an optimum "synergistic" personality type, combining traits of both the charismatic leader and the planner. Implications of the Tri-Partite Theory for selecting educational leaders are then discussed. (TE)