Hierarchy

A hierarchy is an ordering of persons, ideas, or constructs from less to greater importance, in a tiered organizational structure. Organizations may have a hierarchy, both formally and informally: for example, the Senate formally has no internal hierarchy, but informally, senior Senators may "rank" above junior Senators. Doctors of academic disciplines (Ph.D.) in prestigious universities who have been awarded the distinction of occupying the "chair" of academic study are sometimes regarded as "high priests" of their discipline, and the varying levels of academic expertise in Boards of Education as representative of a hierarchy of education. Head coaches of sports teams and their staffs of assistants each constitute a hierarchy of athletic expertise. Military rank is an explicit form of operational hierarchy in every nation, for example, in the United States, from the Commander in Chief, the President, and the Joint Chiefs of Staff, down to the least member of enlisted military personnel.

The word hierarchy comes from hieros, "priest", and archos, "ruler", thus "priest-rule", from the ancient societal ordered levels of authoritative rule by a form of highly educated "priesthood", either secular, as in politics, education and science, or religious, either pagan or Christian. The most readily recognized hierarchy is exemplified by the levels of religious authority in the Catholic Church.

Intellectually, ideas may be expressed in a hierarchical form. An idea common in philosophy is the "hierarchy of needs," a theory proposed by Abraham Maslow, who argued that each individual must meet different needs in ascending order before attaining self-actualization, the pinnacle of human self-awareness.