I’m not positive, but I’m pretty sure that a naked dangling penis brushed lightly against me Tuesday night. This has never happened to me before, at least not at a Museum of Modern Art opening. Two nude figures, a man and a woman, face inward on either side of the narrow main entrance to the museum’s newest exhibit, and unless you choose one of the other entries to the show (provided for the underage, uninterested, or queasy), you’re electing to run the gamut of flesh. So I did. Just as I was thinking "Whew! Made it!" I felt something sort of slide and bounce a bit against my thigh.

Welcome to "The Artist Is Present," the first full-on retrospective of the hard-core Yugoslavian-born performance and body artist Marina Abramovic. While I’ve often found Abramovic’s work hokey, melodramatic and relentlessly narcissistic, there’s no denying that this survey of more than four decades of Abramovic’s work is challenging and will generate outrage (most likely), amazement (possibly) and huge crowds (reliably).

For one thing, there’s a lot of live public nudity. I don’t remember seeing this many breasts in a museum gallery since the last retrospective of the 19th-century French academic painter William-Adolphe Bouguereau, and those were on canvas. After passing between the two gatekeepers, you’ll see two people clad in black who look at and point their fingers at one another, and then two figures with their hair braided together as they sit in a large display case. A naked woman lies on a wall shelf with a skeleton resting on top of her. Then there’s Luminosity. Originally performed in 1997, this optically confrontational work consists of a completely unclothed woman, her arms stretched out, sitting spread-legged on a bicycle seat mounted high on the wall.

Abramovic has always dealt in shock and endurance, punishing the body, pushing viewers out of their comfort zones. In the past, she has posed with an arrow drawn in a bow and pointed directly at her heart, and swapped lives with an Amsterdam prostitute for four hours. This early work can still set your nerves and ideas about art on edge.

At MoMA she is attempting to go the limit, and also to reproduce literally the metaphysical interchange between artists and viewers. For the 700 hours of the exhibition, Abramovic will sit in the middle of MoMA’s atrium, at a table. You can sit across from her. There you will stare at her while she silently stares back. After just two hours on opening night, Abramovic looked exhausted, drained, destroyed. Viewers cried, ran away or looked sick. It’s almost unbelievable that after all the shock and button-pushing going on upstairs, just sitting silently and staring seemed to be the most impossible act of all. Abramovic gets you to understand why many animals hate being looked at by humans. There’s something powerful and uncanny and pure about an unbroken gaze.

Whether you like this exhibition, laugh at it or think of it as a freak-show cliché, there’s little doubt that Abramovic is opening up MoMA, injecting it with life, altering its boring course in ways that the previous dreary Gabriel Orozco show, for example, never did. I may not be an Abramovic convert yet, but I’ll take this show as a step in a direction away from yet another roundup of the usual male Post-Minimalist snooze fest. Oh, and when you walk into her show, I wonder if you’ll go around the two nudes, which one will you face, how fast you’ll go through, whether you’ll stop to look at one, or if anything will brush against you.

"Marina Abramovic: The Artist Is Present," Mar. 14-May 31, 2010, at the Museum of Modern Art, 11 West 53rd Street, New York, N.Y. 10019

JERRY SALTZ is art critic for New York magazine, where this essay first appeared. He can be reached at jerry_saltz@nymag.com.