The judge applied the reasonable person standard to determine if the defendant's actions were justified in self-defense.

A reasonable person would consider all available information before making a decision.

A prudent person is considered to be one who is discreet or discerning to a great degree. A reasonable prudent person would then be one who does not go overboard with their prudence to the point of snobbishness, for example.

Reasonable suspicion

A reasonable person's opinion deserves consideration in a court of law, but a lunatic's does not.