Discretion has the meaning of acting on one's own authority and judgment. In law, discretion as to legal rulings, such as whether evidence is excluded at a trial, may be exercised by a judge. Some view discretion negatively, while some view it positively. Discretion exists at all levels of law enforcement and in many types of front-line bureaucrats. Discretion has been called "the Art of suiting the action to particular circumstances" (Lord Scarman). Those in a position of power are most often able to exercise discretion as to how they will apply or exercise that power. The ability to make decisions which represent a responsible choice and for which an understanding of what is lawful, right or wise may be presupposed.