It's not seeing these works of eminently disreputable beauty in a bona fide art museum that's thrilling (like watching the Marx Brothers demolish "Il Trovatore" in "A Night at the Opera") but the works themselves. The show is a trove of oil paintings that adorned the covers of pulp detective and western and sci-fi magazines -- illustrations that have bled into our subconscious through reproductions and imitations, representing one of our most fragile pop-culture artifacts.

It's estimated that less than 1 percent of all the paintings done in the heyday of the pulps have survived. Robert Lesser, the collector from whose collection the Brooklyn exhibit has been culled, owns about 750. There are other collectors, but the stories of the paintings that didn't survive are sad ones. A fire at the Bronx warehouse of Popular Publications destroyed that company's collection. More telling is what happened when, in 1961, Condé Nast acquired the pulp publisher Street & Smith. Cramped for space in its new digs, the publisher contacted artists about reclaiming their work. Most said no. An auction failed to attract any bids. Condé Nast employees turned down the chance to take the paintings home for free. Finally, Street & Smith's enormous trove, maybe the largest collection of pulp art in existence, was literally hauled to the curb.

In his book "Pulp Art," Lesser answers the question "Why?" For the purposes of this piece, the reasons Lesser provides are an implicit answer to the question of what pulp art has to do with sex. "Pulp art," Lesser writes, "is, to many, offensive art ... Your spouse and other family members would balk at hanging it in the house: the neighbors might see it and it's not nice." (In fact, Lesser told me at the exhibit that he met the daughter of a pulp artist who has saved her father's canvasses in her attic. When he asked her why she didn't display them, she told Lesser the ladies from her church would disapprove.) "Landscapes, seascapes, a bowl of fruit, a vase of flowers, a dog or a cat or a horse, an emotionless canvas of abstract colored shapes, and Norman Rockwell's 'Saturday Evening Post' paintings are nice."

I'd argue that Rockwell is a more complicated case than Lesser implies -- especially his later work of a little black girl being escorted to school with the graffito "Nigger" clearly visible on the wall behind her, or the painting inspired by the Freedom Summer murders of Goodman, Schwerner, and Chaney -- but I take his point in terms of Rockwell's reputation.

That simple but undeniable explanation of why so much pulp art was junked, and the fact that even many of the artists were embarrassed by this work, is the same explanation people would give for not hanging a piece of erotic art in their house, or for even admitting to an interest in the erotic. Like porn and erotica, pulp art does not reach the "nice" areas of our brain. It aims for the gut and the groin, awakening our unacknowledged fantasies, creating the immediate need to possess the object in view, to devour the secrets it promises, assuring us that this visual tease only hints at what's inside. In that way, the covers of pulp magazines functioned as the box covers of porno tapes and DVDs do now (which is why porn producers spend so much time and money on the box cover).

Parents, ministers and the clergy may have characterized pulp as the equivalent of a dark stranger crooking his finger and luring you into a path of vice, but the visual and visceral impact of the covers really did operate like an unsavory come-hither. It's not hard to imagine respectable people surreptitiously buying pulp magazines at the newsstands in the same way that people buy skin mags today.

There is, of course, a line that the pulp magazines would not cross and that, in the '50s, EC comics, with their covers of dismembered limbs and cannibalism, would (in the same way that a Varga girl shows a lot less than an explicit centerfold). But the appeal here is still the lure of the forbidden. This exhibit is necessary. Noir and westerns and detective fiction have all been accorded the respect of being taken seriously. Pulp art has not. The Brooklyn Museum exhibit of selections from Lesser's collection feels like a step on the road to giving these artists their due.

It's inevitable that the paintings will still strike some people as distasteful, or that their exhibition at a serious museum will be seen as a further eroding of the boundaries between high and low art. But one of the functions of museums should be to give the public a glimpse into its own culture. Apart from that, there is the sheer fact that these paintings are ravishingly beautiful. To respond to them, you have to have a taste for the unsubtle, you have to be willing to be seduced by the brightness of color and the dramatic impact of the nasty scenarios they represent.