PRECEDENT, n. In Law, a previous decision, rule or practice which, in
the absence of a definite statute, has whatever force and authority a
Judge may choose to give it, thereby greatly simplifying his task of
doing as he pleases. As there are precedents for everything, he has
only to ignore those that make against his interest and accentuate
those in the line of his desire. Invention of the precedent elevates
the trial-at-law from the low estate of a fortuitous ordeal to the
noble attitude of a dirigible arbitrament.
-- Ambrose Bierce, "The Devil's Dictionary"