Sine qua non (, ) or condicio sine qua non (plural: condiciones sine quibus non) is an indispensable and essential action, condition, or ingredient. It was originally a Latin legal term for "[a condition] without which it could not be", "but for...", or "without which [there is] nothing." Also, "sine qua non causation" is the formal terminology for "but-for causation." Origin and spread As a Latin term, it occurs in the work of Boethius, and originated in Aristotelian expressions. In Classical Latin, the form uses the word (from the verb , , to agree upon), but in later Latin the phrase is also used with , an error in translation as means construction and not condition. It has passed from a merely legal usage to a more general usage in many languages, including English, German, French, Italian and Spanish. General usage U.S. president Andrew Jackson once gave a toast on the occasion of his receiving an honorary doctorate from Harvard University, responding to his listeners, "E pluribus unum, my friends. Sine qua non." In 1938, Jomo Kenyatta, the general secretary of the Kikuyu Central Association and who later became Kenya's first prime minister, wrote that the institution of female genital mutilation was the "condicio sine qua non of the whole teaching of tribal law, religion and morality". He was writing in the context of the missionaries' campaign against female genital mutilation to assert the importance of the rite of passage as an ethnic marker for the Kikuyu, the main ethnic group in Kenya. The phrase appears in the 1967 book on Dahomey culture by Melville J. Herskovits. He wrote about the need to learn the native language: "This does not mean that a knowledge of a native language is a Sine qua non in the study of all problems bearing on primitive cultures. By the use of interpreters and of well recognized and tested techniques, it is possible to obtain the information needed to discover, describe and understand the institutions of a people, and it is such technique that have been employed in this study." The term appears in the 1958 commentary on Article 59 of the Fourth Geneva Convention on the protection of civilians during wartime. In this case, the use of sine qua non refers to the assurance for relief aid to go to the civilian population and not to be diverted toward "the benefit of the Occupying