Final answer:
Pi Phi's leadership philosophy is grounded in servant leadership, focusing on member needs and community development, differing from authoritarian and democratic styles.
Step-by-step explanation:
The cornerstone of Pi Phi's leadership philosophy is servant leadership. This style is characterized by leaders who prioritize the needs of their members, focus on their development, and build a community that acts in the interest of the collective. Servant leadership contrasts with other styles such as authoritarian, where communication is top-down, and democratic leadership, which involves group participation in decision making. While each leadership style can be effective depending on the context, Pi Phi values the servant leadership approach for its emphasis on service and empowerment.