1540s, from Modern Latin Jesuita, member of the Society of Jesus, founded 1533 by Ignatius Loyola to combat Protestantism. Their enemies (in both Catholic and Protestant lands) accused them of belief that ends justify means, hence the sense "a dissembling person" (1630s), and jesuitical "deceitful" (1610s).
A religious order of men in the Roman Catholic Church; its official name is the Society of Jesus. Founded by Ignatius of Loyola in the sixteenth century, the society became the spearhead of the Counter Reformation.
Note: The Jesuit order has a long tradition of vigorous missionary work and of intellectual and scholarly achievement. The Jesuits have also been known historically for their influence, often behind the scenes, in European politics and for their skill and resourcefulness in debate — characteristics that have sometimes led people to mistrust them. In recent years, they have become better known as free-ranging thinkers on religious and political questions.