Arbitrary

Arbitrariness is the quality of being "determined by chance, whim, or impulse, and not by necessity, reason, or principle".

Arbitrary decisions are not necessarily the same as random decisions. For example, during the 1973 oil crisis, Americans were allowed to purchase gasoline only on odd-numbered days if their license plate was odd, and on even-numbered days if their license plate was even. The system was well-defined and not random in its restrictions; however, since license plate numbers are completely unrelated to a person's fitness to purchase gasoline, it was still an arbitrary division of people. Similarly, schoolchildren are often organized by their surname in alphabetical order, a non-random yet still arbitrary method, at least in cases where surnames are irrelevant.

Arbitrary comes from the Latin arbitrarius, the source of arbiter; someone who is tasked to judge some matter. An arbitrary legal judgment is a decision made at the discretion of the judge, not one that is fixed by law. In some countries, a prohibition of arbitrariness is enshrined into the constitution. Article 9 of the Swiss Federal Constitution theoretically overrides even democratic decisions in prohibiting arbitrary government action. The US Supreme Court has overturned laws for having "no rational basis." A recent study of the U.S. asylum system suggests that arbitrariness in decision-making might be the cause of large disparities in outcomes between different adjudicators, a phenomenon described as refugee roulette.

Article 330 of the Russian penal code defines 'Arbitrariness' as a specific crime, but with a very broad definition encompassing any 'actions contrary to the order presented by a law'.

Arbitrary actions are closely related to teleology, the study of purpose. Actions lacking a telos, a goal, are necessarily arbitrary. With no end to measure against, there can be no standard applied to choices, so all decisions are alike. Note that arbitrary or random methods in the standard sense of arbitrary may not qualify as arbitrary choices philosophically, if they were done in furtherance of a larger purpose; in the examples above, discipline in school and avoiding overcrowding at gas stations.

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