There are vast differences in the way human beings live compared to their ancestors hundreds of years ago. However, basic human motivations and needs have not changed. Hence, ancient philosophical texts like the Upanishads, Tao Te Ching, Kabbalah & others have insights that have been used by great leaders through the centuries and have relevance even today. One of the key ideas you can derive from these books is the concept of Servant Leadership.
A servant-leader focuses primarily on the growth and well-being of people and the communities to which they belong. While a traditional leader looks to accumulate and exercise of power, the servant-leader shares power, puts the needs of others first and helps people develop into leaders themselves.