“Drawing the line” to distinguish conduct that society declares within the bounds of law and morality and conduct that is deemed worthy of punishment or condemnation frequently raises an ethical dilemma. Individual instances of enforcement may seem unfair, but making an exception for every such case risks rendering a law or rule incomprehensible or useless. If a rule or law has any validity, it must be enforced, and if it is enforced consistently, sometimes that enforcement will seem unjust. Indeed, enforcement may be unjust from the point of view of the party penalized and its allies. But enforcing the rule may still be justified in order to keep a valid rule functional.

An example of this is the latest attempt by Major League Baseball to kick 89 year-old Johnny Pesky off the Boston Red Sox bench during the baseball season. This happened during the 2004 season as well, when MLB decided to enforce a long-standing rule against personnel who had no official duties with a team sitting in the dugout. Pesky is an unusual case, a former Sox star, coach, manager, and broadcaster who represents a long Red Sox tradition stretching back more than 60 years, and who serves as a combination icon/father figure/good luck charm/mascot when he isn’t hitting the player pop flies in fielding practice or signing autographs for fans. In the euphoria following the team’s storybook championship in 2004, the Red Sox returned Pesky to the bench in 2005, and the baseball powers let the infraction go unpunished through last season. But now it wants to enforce the rule again, so Pesky, whose wife recently died and who has nothing left in life but his connection to the team, must go.

This certainly feels petty and cruel. But it is not an unreasonable rule. Allowing teams to load up their benches with friends, celebrities, fans and supporters is a recipe for abuse; if an exception is made for Johnny Pesky, can Spike Lee and Donald Trump be far behind? Pesky’s situation is, well, exceptional. But a “Pesky Exception” would be a slippery slope. Could MLB then deny a seat on the New York Yankee bench to Phil Rizzuto, a Yankee shortstop who was a contemporary of Pesky’s? Yogi Berra? Rizzuto and Yogi Berra? Would every team get a designated old-time star? What about an old-time star’s ne’er do well son, as a favor to Dad? From Pesky’s point of view and that of a Red Sox fan, I’d love to see MLB make an exception. But I can hardly say that it is unfair for it to enforce the rule.

An even tougher instance of a line causing ethical doubts was the recent Pennsylvania case of Commonwealth v. Hooks. The defendant Hooks was sentenced for “aggravated indecent assault on a person less than 16 years of age, statutory sexual assault, and indecent assault.” He was a door-to-door vacuum cleaner salesman, and he had sexual relations with a girl who opened the door for him at one of the houses he visited (he is obviously one compelling salesman) on the day before her 16th birthday. The jury convicted him of statutory rape; had the girl been sixteen, there would have been no crime. Hooks, who was 23, appealed on the basis that Pennsylvania courts had in the past applied a rule from the English Common Law that “for purposes of computing a person’s age, one attains the age in question on the day prior to the anniversary of his birthdate.”

The court rejected the appeal, and declared that the common sense rule declaring one’s age to change on one’s birthday would and should govern. So just twenty-four hours—one day— made the difference in determining whether or not Hooks was a criminal. Was the girl any more mature and capable of consenting to sex on her birthday than the day before? Highly unlikely. But arguments that the day before should be treated the same as the birthday itself leads to a paradox. If the day before makes no difference in the resolution, why not extend the principle to the day before that, and the day before that, until we’re reached the girl’s fifteenth birthday? Drawing the line where the court did is undoubtedly hard on Hooks, and arbitrary as it applies to him. But the line is reasonable, and once drawn, it is correct to apply it strictly. Every rule will generate anomalies that seem unfair, illogical or unintended; this is the essence of Kurt Gödel’s “Incompleteness Theorem.” But as Gödel observed in his Second Theorem, changing the rule or law to adapt to the anomaly ends up destroying its integrity.

The wisest principle is that following a reasonable law or rule even when a particular result seems to be unjust is still better in the long run than making an exception to it. Often this inspires a creative solution while keeping the rule intact: the Red Sox, for example, could hire Pesky as some kind of coach; a lenient sentence for Hooks could take the technical nature of his offense into account.

And sometimes the most ethical thing is to break the rule and make an exception…because even wise principles don’t work every time.