sine qua non

plural sine qua nons · plural sine quibus non · alternative sinequanon · alternative sine quâ non

1. An essential or indispensable element, condition, or ingredient.

   Near-synonyms: dealbreaker, necessary condition

   4 more examples

   it is hardly likely he would have found any one so singularly interesting and fascinating as Margarita Riccardini; for the striking and animated beauty of her father was softened and relieved by that peculiar something, half modesty, and half pride, which is the characteristic of English loveliness, and which every Englishman requires as a sine qua non ere he resigns himself to a bondage it is the habit of his nature, or the result of his privileges, to admit reluctantly.

   1842, [anonymous collaborator of Letitia Elizabeth Landon], chapter XXIX, in Lady Anne Granard; or, Keeping up Appearances. […], volume II, London: Henry Colburn, […], →OCLC, page 79

   Beauty, grace, and accomplishments are, as I said before, a sine qua non, but as Basil is already the colonel of a crack cavalry corps, and has other military honours promised him in the near future, as also by reason that his father is Governor-General of the gubernium of Odessa, and will leave his son abundant wealth as well as his title of count, I think I have a right to expect something more in his future wife than mere accomplishments and good looks.

   1883 January 12, James S[kipp] Borlase, “Darker than Death; a Tale of the Russia of To-day”, in The Hull Packet and East Riding Times, number 5,126, Kingston upon Hull, E.R.Y., chapter XVI (The Countess Takes Precautions and the Count Drives Bargains), page 3, column 3

   Literature, instead of being an accessory, is the fundamental sine qua non of complete living.

   1909, Arnold Bennett, chapter I, in Literary Taste: How to Form It

   […] whereas some degree of political freedom is a sine qua non condition for contestation, democracy cannot be sufficiently defined in terms of “liberties”[…]

   2000, A. Przeworski, M. Alvarez, J. Cheibub, F. Limongi, Democracy and Development, Cambridge University Press, page 34

   Synonyms: nonnegotiable, prerequisite, dealbreaker, necessary condition