Sex and fashion have much in common. Indeed, they depend upon each other. And yet both industries share a curious feature: Men are almost always absent or incidental — or safely behind the scenes. In the case of pornography, it’s clear why men have such small and faceless role. But when it comes to fashion, where are the guys?

That question animates a new show at the New York Public Library, “A Rakish History of Men’s Wear,” which runs through April 7. Though the show does an exemplary job of compressing the history of men’s fashion into a digestible and entertaining display, it never really answers the riddle of why men went from being the very center of fashionable display to its furthest margins.

One of the central problems with contemporary men and clothes is simply that no self-respecting man wants to admit an interest in them. The show presents the rake as a liberating figure in the history of men’s fashion, but it confuses the rebellious rake with the refined dandy. Few men may want to think of themselves as dandies these days, but the true dandy is not who we imagine.

Let’s see where it all went wrong. The standard history of men’s clothing goes like this: In the beginning, men were warriors.They dressed to scare their opponents. Military prowess begat social status, and the lives of elite men became filled with displays of power and athleticism. The fashionable man’s wardrobe is a catalog of these twin themes of military might and physical prowess. The tuxedo is a modified military uniform.The ubiquitous polo shirt owes its popularity to the Rubirosa-style playboy. Whether it’s aviator sunglasses, motorcycle jackets, or the many varieties of riding boots, what a man wears evokes some sort of derring-do. Go in any direction with men’s clothes and you’ll find your way back to the barracks or the locker room. An interest in clothes was, for most of history, an interest in masculine pursuits.

“A Rakish History of Men’s Wear” begins on the sun-drenched field of battle. Here we see the evolution from body paint and plumage to black armor to gilt-braided uniforms to white tie and medals. This show is particularly good at showing the flow of male costume from individuality to order. The first warriors — the noble but ferocious Greeks — bedecked themselves to achieve eye-popping intimidation. Warfare evolved into something more complex, but the scare factor remained. The point is cleverly made in the portrait of the Duke of Wellington: The viewer’s eye inevitably falls on the leopard-patterned saddle blanket on the field marshall’s horse.

As war, society, and industry brought more and more men together in communal action, standout distinction morphed into rank — first military, then economic and social. The dual portraits of Napoleon, one as hero, the other as godlike emperor, show this transition with admirable economy.

The turning point in the show comes with an early 20th-century drawing by Charles Dana Gibson of a young woman choosing between two suitors. The scene is set at a ball and both men are in formal clothes. The older man is clearly distinguished, wearing a white stock — the formal tie of the 19th century — along with a sash of honor and a prominent medal. The younger, more attractive man wears a black bow tie — the formal attire of the 20th century. The point is meant to highlight the subtle distinctions in dress — but it also adds the element of sex into the story. And that’s where the action is.

Curator Paula Baxter began assembling the display from the top down, starting with the title “A Rakish History,” and working her way into the mists of masculinity. The figure of the rake does add a new element to the story of men’s clothes. Ms. Baxter tries to suggest that the rake evolved from the dandy. She shows us all the important figures in the history of dandyism, from Byron, Brummell, Beerbohm, and Baudelaire, to — moving beyond the Bs — Count D’Orsay. Then she introduces rakish rebels like Sinatra, Brando, and that wannabe rake, Sean Combs.

Unfortunately, the dandy really isn’t a precursor of the rake. More than anything else, the dandy is a man of exceptional taste, not an outrageous figure. The dandy relies on his taste — his art, if you will — for his social stature. This was Brummell’s story. The rake is a more dangerous figure.

To illustrate the confusion between dandy and rake, let’s look at someone who was left out of the show. He’s a character in a movie who appears to be a rake but is really a dandy. In the classic “It Takes a Thief,” Grace Kelly’s character falls for a dangerous criminal on the French Riviera played by Cary Grant. She is attracted to him because she thinks he’s stylish and dangerous. In other words, she’s attracted to him because he’s a rake. But the mystery unveiled in the movie is that John Robie, the cat burglar, is actually an honorable, principled man.

An American who fought in the French Resistance, he has acquired pitch-perfect taste, impressing a plummy British insurance executive with his manners, his villa, his luncheon menu, and his choice of wines. Here we see the dandy at his best: understated, elegant, and world-wise. Like Beau Brummell, he is entirely self-made. He’s also sincere, yearning to be domesticated by Grace Kelly.

The exhibit has a bit of Grace Kelly problem, too. It gets distracted by the idea of the rake. Unfortunately, it also loses its sense of style as it moves into the present. The Rat Pack is one of the last groups in which a dandy and a rake could stand together.(For those keeping score at home, Peter Lawford would be the rake, and Dean Martin is the dandy.)

After the Rat Pack, the wheels start to come off. We see John Wayne in cowboy gear, and Brando as the Wild One. Also on display is a fashion spread from an October 1974 issue of Playboy. The conceit of the fashion spread is that a man and his girl are getting dressed for a night out. That gives Playboy the opportunity to show off the models spectacular breasts. But next to that impressive display, the clothes are dull and pointless. (Even without the exhibitionism, the clothes would be hideous.)

The final proof of the rake’s impotence comes in the form of Sean Combs. His two photographs — both sullen and sexless — show his fashion sense is as limited as his bad boy persona. That may only prove that if the history of men’s clothes is anything like the history of men, it is the fighter who ultimately means much more than the lover.