Necessary or necessity may refer to: *
Need A need is dissatisfaction at a point of time and in a given context. Needs are distinguished from want The idea of want can be examined from many perspectives. In secular societies want might be considered similar to the emotion desire, which ...
** An action somebody may feel they must do ** An important task or essential thing to do at a particular time or by a particular moment * Necessary and sufficient condition, in logic, something that is a required condition for something else to be the case * Necessary proposition, in logic, a statement about facts that is either unassailably true (tautology) or obviously false (contradiction) * Metaphysical necessity, in philosophy, a truth which is true in all possible worlds * Necessity in modal logic * Necessity good in economics ;Law * Doctrine of necessity, a concept in constitutional law * Military necessity, a concept in international law * Necessity (criminal law), a defence in criminal law * Necessity (tort), a concept in the law of tort * A necessity in
contract law A contract is a legally enforceable agreement between two or more parties that creates, defines, and governs mutual rights and obligations between them. A contract typically involves the transfer of goods, services, money, or a promise to ...
;Other * , a poem by Letitia Elizabeth Landon being part of ''Three Extracts from the Diary of a Week'', 1837. * "Necessary" (song), by Every Little Thing, 1998 * A bathroom or
toilet A toilet is a piece of sanitary hardware that collects human urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination r ...
, in some languages (in English this is an archaic usage) * An economic need enunciated by US President Franklin D. Roosevelt in his 1944 Second Bill of Rights * ''Necessity'' (novel), of 2016 by Jo Walton * Necessary Records, UK record label

See also

* * * * * Bare Necessities (disambiguation) {{disambiguation