Meet The Reasonable Person. He’s a self-righteous prig who, when not watching product instruction videos for fun, spends his free time poring over driver safety manuals.

The Reasonable Person wouldn’t dream of answering his cellphone while driving. He would refuse without hesitation to serve alcohol to a drunk. Ope­ra­ting heavy equipment while under the influence of sleep-inducing medicine? Never!

In short, The Reasonable Person is like the cousin you hated because your mother constantly said he was perfect.

Why should you care about The Reasonable Person? Be­cause that is the standard used by courts to determine if someone has been negligent. Some­day, you may have to prove that you acted like The Reasonable Person.

The Supreme Court opines regularly about The Reasonable Person, which is a standard that must be met by both sides of the docket. The plaintiff may be negligent for running a stop sign and hitting the defendant. The defendant may also be negligent for avoiding the accident when he observed the plaintiff running the stop sign. Both failed to act like The Rea­s­on­able Person.

In fact, the Supreme Court is so enamored with the standard that it has thrown out specific defenses like imminent peril, last clear chance and assumption of the risk in favor of an all-encompassing defense of comparative negligence. The jury is asked to determine the percentage of negligence of both the plaintiff and the defendant.

The term negligence means (for an act) the doing of that which a person of ordinary prudence would not have done under the same or similar circumstances, or (for failing to act) the failure to do that which a person of ordinary prudence would have done under the same or similar circumstances.

The actor is required to recognize that his conduct involves a risk of causing an invasion of another’s interest if a reasonable man would do so while exercising (a) such attention, perception of the circumstances, memory, knowledge of other pertinent matters, intelligence and judgment as a reasonable man would have; and (b) such superior attention, perception, memory, knowledge, intelligence and judgment as the actor himself has.

This isn’t a simple test. For example, for medical matters a doctor is held to a higher Reasonable Person standard than a non-medical professional would be, because the doctor has superior knowledge.

Parsing it further, the higher standard applies when the doctor is acting in his capacity as a doctor — but what is it the correct standard when the doctor is a patient?

The Supreme Court recently decided a negligence case involving just that point. Dr. David Axelrod, a psychiatrist, went in to see Dr. Richard Jackson, an internist, for abdominal pain. Dr. Jackson treated him with a laxative. Unfortunately, Dr. Axelrod actually had diverticulitis, and two days later had to have emergency surgery to have his colon removed.

Dr. Axelrod sued Dr. Jackson for malpractice.

The case turned on whether Dr. Axelrod acted reasonably in reporting his symptoms. Diverticulitis is readily apparent if the patient reports pain in the lower left quadrant of his stomach. Dr. Axelrod never indicated that location for his pain.

The Supreme Court held that both Dr. Jackson and Dr. Axelrod should be held to the higher standard — that of a Reasonable Person with superior knowledge. Thus, Dr. Axelrod’s failure to properly report his symptoms violated that standard, and constituted negligence.

As a matter of law, The Reasonable Person isn’t perfect. As a matter of fact, however, the jury will second-guess your actions as if they had occurred in vacuum. They will sit in a small, brightly lit jury room and judge whether you, the actor, acted without reference to anger, fear, illness, distraction or fatigue.

Doesn’t seem reasonable, does it?