Secret Society

A secret society is an organization about which the activities, events, inner functioning, or membership are concealed. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence agencies or guerrilla warfare insurgencies, that hide their activities and memberships but maintain a public presence.
[frontispiece from "The Epistles of the Brethren of Purity".jpg|upright=1.4|thumb|The Brethren of Sincerity) were a secret society[1 of Muslim philosophers in Basra, Iraq, in the 9th or... meer