“Laughter is easily restrained by a very little reflection,” wrote the perpetually pedantic Philip Dormer Stanhope to his son in 1758, “but as it is generally connected with the idea of gaiety, people do not enough attend to its absurdity.” In his observation, Stanhope, a former ambassador and member of Parliament, managed, like many a parent, to get it right and wrong at the same time. Does not laughter's power reside precisely in its unwillingness to be restrained, its resistance to reasonable reflection? Yet it is true that explanations of what makes us laugh are perhaps not as widely attended to as those of what makes us depressed, angry, or insane. Earlier in his letter about mindful comportment, Stanhope, who wrote 448 letters to his bastard son generally on the topic of how to win friends and influence people, quoted the French moraliste La Rochefoucauld, “The heart almost always dupes the mind.” In the case of humor, it might be more accurate to say that it enlists the mind without its consent. Since there is an element of absurdity in it, humor, like the heart's love, often evades analysis—both because it feels magical, ineffable, and because we fear that intense scrutiny will kill it, the pleasure it affords us, as it were in the eye.

To read the literature on humor is only to have some suspicions justified. There is a greater danger of boredom, all the fun of the subject sapped, like trying to divine the mysteries of sex from an illustrated how-to manual. Aristotle, not exactly known as an amphora of laughs, thought it prudent to dedicate a book of his Poetics to the subject of comedy. Somewhere along the way from ancient Athens to Renaissance Italy, it got lost in the shuffle of papyri, and with it some inkling of what the first great literary critic had to say about why the chicken crossed the road. We might be the better for it. He did, however, offer up at least one chestnut: “The aim of comedy is to exhibit men worse than we find them; that of tragedy, better.” While other of Aristotle's close observations have been remanded to the waste heap—flies have four legs, women fewer teeth than men—this one has stuck. If we are moved to tears when a great man falls, then we'll laugh when a low man slips on a banana.

Even though we know Aristotle devoted more attention to tragedy, he saw in comedy a primary expression of the human condition. Laughter is its own form of catharsis, and it was the messiness of this particular ejaculation that drew such a round condemnation from Stanhope:

Having mentioned laughing, I must particularly warn you against it—I could heartily wish that you may often be seen to smile but never heard to laugh while you live. Frequent and loud laughter is the characteristic of folly and ill manners; it is the manner in which the mob express their silly joy at silly things, and they call it being merry.

Maybe he's not all wrong here, but he's certainly an asshole. Much of what elicits laughter is as unrefined as crude oil, and, like that greasy excrement of the earth, low humor doesn't really lose its potency over time.

Poggio Bracciolini, a fifteenth-century papal secretary and book hunter who rediscovered Lucretius’ On the Nature of Things, jotted this one down about a pregnant simpleton in what's considered one of the modern world's first joke books:

She had long been enduring acute pain, and the midwife, candle in hand, inspected her private parts, in order to ascertain if the child was coming. “Look also on the other side,” said the poor creature. “My husband has sometimes taken that road.”

It's as worthy of a chuckle as the exclamations in this letter from 1777, postmarked Mannheim:

Oh my ass burns like fire! What on earth is the meaning of this!—maybe muck wants to come out? Yes, yes, muck, I know you, see you, taste you—and—what’s this—is it possible? Ye Gods!—Oh earof mine, are you deceiving me?

It's just a nice kicker that the serious scatological complaints and pained posterior in question belong to Wolfgang Amadeus Mozart. You see, poop always comes out of our butts, and more often than not it smells like shit; sex is forever funny because the act of “making the beast with two backs,“ as William Shakespeare called it, is at once natural and completely ridiculous.

While the truth isn't always funny, what's funny is almost always true. Perhaps that's why humor, and its attendant laughter, was vilified long before Stanhope could rain on the parade. St. John Chrysostom observed in the fourth century, “Laughter often gives birth to foul discourse, and foul discourse to actions still more foul. Often from words and laughter proceeds railing and insult; and from railing and insult, blows and wounds; and from blows and wounds, slaughter and murder.” While Charles Baudelaire might not have seen the connection between murder and merriment as quite so direct, he too saw that the devil was at work in a good joke. “Laughter is satanic,” he wrote in 1855. “It is therefore profoundly human.” It's the same diagnosis, different prognosis. While he may be considered a master of modernity, Baudelaire with his judgment that “in man laughter is the consequence of his idea of his own superiority,” he doesn't differ much from that classic curmudgeon Thomas Hobbes, who observed,

Sudden glory is the passion which maketh those grimaces called laughter, and is caused either by some sudden act of men’s own that pleaseth them or by the apprehension of some deformed thing in another, by comparison whereof they suddenly applaud themselves.

This long line of thinking is narrow and brittle, though, and it breaks under the pressure of even the lightest of witticisms by someone like Oscar Wilde. When young Jack Worthing confesses to Lady Bracknell in The Importance of Being Earnest that he has lost both his parents, and she replies, “Both? That seems like carelessness,” we are not smiling at something deformed but well-turned. Of course such phrasing can come sharply with a mean spirit, as when H.L. Mencken characterizes the rhetorical style of President Warren G. Harding:

It reminds me of a string of wet sponges; it reminds me of tattered washing on the line; it reminds me of stale bean soup, of college yells, of dogs barking idiotically through endless nights. It is so bad that a sort of grandeur creeps into it. It drags itself out of the dark abysm (I was about to write abscess!) of pish, and crawls insanely up the topmost pinnacle of posh. It is rumble and bumble. It is flap and doodle. It is balder and dash.

The assessment is funny not because it's mean but because Mencken is having fun. He was but a poor scribbler and had neither the hope of becoming president nor the delusion this his words would depose the one in power. It's the same fun that animated Dorothy Parker, who, when asked to use the word horticulture in a sentence, replied, “You can lead a horticulture, but you can’t make her think.”

Maybe the things that make us laugh aren't all that mysterious or magical, for, like a magic trick, they rely on careful misdirection—or, when accidental, a blurring of what is and what should be. “Why do we smile when a child puts on a man’s hat?” asked Herbert Spencer, the man who coined that fun phrase “survival of the fittest,” before he lapsed into a wonderful pontification of pseudo-physiological balderdash. It's a truth universally acknowledged that children are funny because they do and say the darnedest things. They are like us, but not quite; we were them, they will be us. That's a constant, not bound to change anytime soon, and neither will our need for comedy: life can be a drab affair, often tragic, and sometimes one can only laugh at it in order to live. A Holocaust survivor and therapist, Viktor Frankl noted that “the attempt to develop a sense of humor and to see things in a humorous light is some kind of a trick learned while mastering the art of living” and “it also follows that a very trifling thing can cause the greatest of joys.” So it was that Frankl and his fellow captives found themselves aboard a train out of Auschwitz, fearing the worst: that they were destined for Mauthausen, the dreaded labor camp. In order to reach it, they knew they would crossover the Danube on a bridge. “Those who have never seen anything similar cannot possibly imagine the dance of joy performed in the carriage by the prisoners when they saw that our transport was not crossing the bridge and was instead heading ‘only’ for Dachau.” Comedy and tragedy aren't always as neatly cleaved as Aristotle would have liked, and neither is truly full without a touch of the other.

Frankl and Stanhope were both concerned with “mastering the art of living,” but their positioning of humor within that art could not have been more different. Ever concerned with outward appearances over inner realities, Stanhope completed his little screed against laughter by finally providing his son with a bit of sober self-reflection. “I am neither of a melancholy nor a cynical disposition and am as willing, and as apt, to be pleased as anybody,” he confessed, “but I am sure that, since I have had the full use of my reason, nobody has ever heard me laugh.” His claim is ridiculous. If only Stanhope had the stomach to laugh at himself—for, in the end, it saves us a good deal of sound and fury to remember we are all idiots, and the joke is always on us.