By a vote of 183-50, town meeting members in Middleborough, Mass., last week approved a bylaw making public cursing a civil offense and authorizing police to enforce the ban by fining offenders $20.

Town Hall may find it hard to collect on those fines. Assuming Cohen v. California is still good law, the First Amendment’s protection of free speech extends to using four-letter words in public, and as soon as the new ordinance is challenged it will almost certainly be struck down. Legally, town authorities don’t have a leg to stand on. But their concern with enforcing public standards deserves better than the eye-rolling mockery it has been getting.

Cohen was the 1971 case in which the Supreme Court overturned the conviction of a Los Angeles man arrested for disturbing the peace after he appeared in municipal court wearing a jacket with the F-word on it. (The jacket, with the word spelled out, read: “F— the Draft.”) Writing for the majority, Justice John Marshall Harlan conceded that “the particular four-letter word being litigated here is perhaps more distasteful than most."  Nevertheless, he continued, "one man’s vulgarity is another’s lyric” – and “it is largely because governmental officials cannot make principled distinctions in this area that the Constitution leaves matters of taste and style so largely to the individual.”

When it comes to freedom of speech, my convictions are generally libertarian: The proper response to bad speech is better speech. The First Amendment wouldn’t be worth much if it protected only anodyne and sensible expression. What makes it such a vital safeguard of American liberty is that it shields ugly and obnoxious speech as well – even that of odious hate groups or lying propagandists. I line up with Oliver Wendell Holmes Jr., who wrote more than 80 years ago that the Bill of Rights safeguards not merely “free thought for those who agree with us but freedom for the thought that we hate.”

Freedom of expression, however, isn’t the only value a healthy civil society depends on. Common courtesy and reasonable standards of public conduct matter too. In other areas most of us take it for granted that the rights of communities, not just those of individuals, are entitled to some deference. Middleborough wouldn’t have made national headlines last week if town meeting members had voted to impose fines on anyone trashing public spaces with litter or graffiti or dog droppings. Should it really make Page 1 when civic leaders look for a way to curb the befouling of public spaces with loud and unrestrained cursing?

Maybe Middleborough merchants and officials are exaggerating what they say has become a plague of public profanity, especially among the young. (“They’ll sit on the bench and yell back and forth to each other with the foulest language,” says former selectwoman Mimi Duphily.)  But there can’t be much doubt that vulgar speech now courses openly through American society to a degree that would have been unthinkable just a few decades ago.

The potty-mouthing of our culture is ubiquitous. Go to a new play, take in a movie, turn on a prime-time TV show, and you’re all but guaranteed to encounter the kind of language that used to get mouths washed out with soap. Some shows revel in their crudity: “South Park” is notorious for its foul-mouthed fourth-graders. One episode of “The Wire” contrived to use the F-word 38 times in under four minutes.

One man’s vulgarity is another’s lyric? These days it can be another’s Grammy-winning hit song: Just ask Cee-Lo Green. Or it can be another’s campaign rhetoric: When he was publicly flirting with a presidential run last year, Donald Trump delivered a profanity-laced speech to an audience that cheered and applauded each time he dropped the F-bomb.

Let sewage flow into a river long enough, and eventually it may catch fire. Ignore graffiti and broken windows long enough, and eventually anti-social crime can make a neighborhood intolerable. What happens to a culture in which obscenity and raunchy language are omnipresent?

“That the air may at times seem filled with verbal cacophony is … not a sign of weakness but of strength,” the Supreme Court said in Cohen. “In what otherwise might seem a trifling and annoying instance of individual distasteful abuse … fundamental societal values are truly implicated.”

But that was in 1971. Today we are a lot further down the slippery slope. The crudity polluting American life no longer seems merely “trifling and annoying.” Middleborough’s solution is all wrong, but the problem it’s trying to address is no small matter.

(Jeff Jacoby is a columnist for The Boston Globe. His website is www.JeffJacoby.com).