Leadership is both a research area and a practical skill encompassing the ability of an individual or organization to 'lead' or guide other individuals, teams, or entire organizations. Specialist literature debates various viewpoints, contrasting Eastern and Western approaches to leadership, and also (within the West) United States versus European approaches. U.S. academic environments define leadership as 'a process of social influence in which a person can enlist the aid and support of others in the accomplishment of a common task'.Leadership is a matter of intelligence, trustworthiness, humaneness, courage, and discipline ... Reliance on intelligence alone results in rebelliousness. Exercise of humaneness alone results in weakness. Fixation on trust results in folly. Dependence on the strength of courage results in violence. Excessive discipline and sternness in command result in cruelty. When one has all five virtues together, each appropriate to its function, then one can be a leader. — Jia Lin, in commentary on Sun Tzu, Art of War Leadership is both a research area and a practical skill encompassing the ability of an individual or organization to 'lead' or guide other individuals, teams, or entire organizations. Specialist literature debates various viewpoints, contrasting Eastern and Western approaches to leadership, and also (within the West) United States versus European approaches. U.S. academic environments define leadership as 'a process of social influence in which a person can enlist the aid and support of others in the accomplishment of a common task'. Studies of leadership have produced theories involving traits, situational interaction, function, behavior, power, vision and values, charisma, and intelligence, among others. Sanskrit literature identifies ten types of leaders. Defining characteristics of the ten types of leaders are explained with examples from history and mythology. In the field of political leadership, the Chinese doctrine of the Mandate of Heaven postulated the need for rulers to govern justly and the right of subordinates to overthrow emperors who appeared to lack divine sanction. Pro-aristocracy thinkershave postulated that leadership depends on one's 'blue blood' or genes.Monarchy takes an extreme view of the same idea, and may prop up its assertions against the claims of mere aristocrats by invoking divine sanction (see the divine right of kings). On the other hand, more democratically inclined theorists have pointed to examples of meritocratic leaders, such as the Napoleonic marshals profiting from careers open to talent. In the autocratic/paternalistic strain of thought, traditionalists recall the role of leadership of the Roman pater familias. Feminist thinking, on the other hand, may object to such models as patriarchal and posit against them emotionally attuned, responsive, and consensual empathetic guidance, which is sometimes associated with matriarchies. Comparable to the Roman tradition, the views of Confucianism on 'right living' relate very much to the ideal of the (male) scholar-leader and his benevolent rule, buttressed by a tradition of filial piety. Machiavelli's The Prince, written in the early 16th century, provided a manual for rulers ('princes' or 'tyrants' in Machiavelli's terminology) to gain and keep power. In the 19th century the elaboration of anarchist thought called the whole concept of leadership into question. (Note that the Oxford English Dictionary traces the word 'leadership' in English only as far back as 1821.) One response to this denial of élitism came with Leninism - Lenin (1870-1924) demanded an élite group of disciplined cadres to act as the vanguard of a socialist revolution, bringing into existence the dictatorship of the proletariat. Other historical views of leadership have addressed the seeming contrasts between secular and religious leadership. The doctrines of Caesaro-papism have recurred and had their detractors over several centuries. Christian thinking on leadership has often emphasized stewardship of divinely provided resources—human and material—and their deployment in accordance with a Divine plan. Compare servant leadership.