"Constantin Brancusi: The Essence of Things," June 11-Sept. 19, 2004, at the Guggenheim Museum, 1071 Fifth Avenue, New York, N.Y.

Americans from the get-go treated the sculpture of Constantin Brancusi with the ardor and acquisitiveness with which they embraced the work of his contemporary, Pablo Picasso. The art Brancusi carved, modeled and cast in wood, stone, plaster and metal, from 1905, soon after he left Romania, until 1957, when he died in Paris at the age of 81, was collected in depth and entered several East Coast museums. Of the seven one-person shows mounted worldwide before 1970, six were held in New York and Philadelphia.

Brancusi remains popular in the U.S. In 1989, the late artist Scott Burton famously installed Brancusi sculptures at the Museum of Modern Art separately from their pedestals, while also presenting the pedestals on their own as independent works. Nine years ago, the Philadelphia Museum of Art co-organized a huge retrospective accompanied by a hefty, scholarly catalogue that immediately became the standard reference. Now, "Constantin Brancusi: The Essence of Things", the latest survey, which is comprised of just 34 sculptures, is about to end its run at the Guggenheim Museum, where it has been radiantly installed by the incomparable Carmen Gimenez, who co-organized the show with Matthew Gale of Tate Modern.

In the wake of the PMAs definitive exhibition in 1995, it is a thrilling surprise this summer to discover that much remains to be learned about this astonishing artist. Sometimes, as he might have said, the forest gets lost for the trees. Here, the focus is on the artists starkest stone and wood works: recumbent ovoids, sleek heads, truncated torsos, standing figures and erect birds. A spare, clean look prevails.

Brancusi was much more than a portrait maker who flirted with abstraction. For every Mlle Pogany, Madame L.R., Eileen and Nancy Cunard, he made two or three other works that relate to religious matters, folk tales and philosophical concerns. This show clarifies the nature of his subject matter from its outset.

Visitors to the Guggenheim are encouraged to walk down the spiral so that they could view the art chronologically, but the exhibition also reveals much when we proceeded up the ramp. Three versions of The Kiss (1907-08, 1908 and 1916) anchor one end, and Adam and Eve (1921), the other. Ordinarily, these works are not related to one another.

Due to the rise of nonrepresentational art, certain sculpture types have for decades been all but ignored. Certainly, two-figure portrayals head the list, and that is the genre, which includes Lorenzo Berninis Apollo and Daphne and Pluto and Proserpina, to which these early and middle period carvings by Brancusi belong.

When the three versions of The Kiss are displayed as a group, as here, the seemingly weathered stone version of 1908 betrays its stylistic debt to the sort of squat, compact capitals found in Medieval churches and cloisters. Think Moissac or Autun. Brancusi composed all four sides of each work carefully, giving the woman lovely Rapunzel-like hair and the man a shorter cut. Unlike Rodins works, with which they are frequently compared, the figures of the Romanians Kiss appear to already be coupling. The sculptor shaped their eyes into a vulva-like configuration and their suctionesque lips further meld them together. Referring to a later Kiss, sculptor Malvina Hoffman asked Brancusi, "I see the forms of two cells that meet and create life. . . the beginning of life through love. Am I right?" Brancusi replied, "Yes, you are."

By 1921, Brancusi, with his mixture of primitivism and (way more) sophistication, was a modernist. He conceived Adam and Eve as one carved, stacked wood sculpture. Only its title suggests its life-affirming as well as religious overtones. But they are there. And once these four sculptures are interpreted this way, others appear in a new light.

Consider Beginning of the World and Sculpture for the Blind. At opposite poles from the multi-figure compositions, both instead call to mind the sort of polished rocks -- considerably enlarged -- that you might find on a beach or along a riverbed. These beautiful, elegant marbles from ca. 1920 have a pronounced philosophical orientation.

Sculpture for the Blind refers not to a person with a disability but to all those with 20-20 vision who nevertheless still cannot see. And Beginning of the World, which sits on a shiny disc that is part mirror, part pool of water, raises the old conundrum -- which came first, the chicken or the egg? But the canny, bearded Romanian also seems to be trying to figure out whether to back Charles Darwins theories or accept Adam as progenitor.

In the period between two world wars, the fathers of early modernism -- artists as well as composers -- made animals the subjects of many works. Sergei Prokofievs Peter and the Wolf is not an isolated example. Moreover, these representations relate to each creators individual concerns. Alexander Calder, for example, stocked a three-ring circus with lions, elephants and kangaroos, which bring smiles to the faces of their beholders.

From marble, Brancusi carved a large Flying Turtle, The Seal and several varieties of birds, including a Cock and Two Penguins. And these are just the sorts of creatures that populate the Galapagos Islands where Darwin hatched his theory of evolution. What a grand metaphor for describing the way Brancusi worked in series -- and also for his place in the history of art.

Because this is such a concentrated exhibition, it is possible to get up close and personal with many of these stunning works. Over and over again, Brancusi dazzles with feats of balance. Marbles are displayed toward the edges of their pedestals rather than plunked down in their centers. This enhances the grace of, say, Torso of a Young Girl (1922) and adds to the whimsy of Young Bird II (1925). The endearing awkwardness of Little French Girl (The First Step III) has as much to do with the way the child in a turtle skirt is positioned on the wood block as it does with the turn of her feet.

But then many of Brancusis sculptures dont just rest on their supporting bases. Rods run through their cores and root them into the various practical as well as artful shelves, discs, cruciforms and such that sit beneath them. This engineering explains part of the magic of the soaring Bird in Space series, not to mention the tuneful Maiastra and the bewitching The Sorceress (1916-24). These days, whether because of wear and tear or aging, a number of slender poles, such as the ones used in Mlle Pogany II (1919), are visible. There is a plugged up hole at the base of the head of Sleeping Muse I (1909-10), and Head of a Child (First Step), a plaster from 1917, has a hole that was never filled.

And while were talking about the imperfect perfect, what about Sleeping Muse III or IV (ca. 1917-18)? Leant to the Guggenheim from a private collection, the piece is on public view for the first time -- it wasnt included at Tate Modern, where this show opened. Theres an astonishing flaw -- an out-of-character chisel mark -- above the right eye. Has this work just come to light because it is a damaged sculpture Brancusi never intended to exhibit?

Whatever the circumstances of its appearance, it is fascinating to compare the blemished work with the earlier version a few feet away.

From time to time, scholars wonder how Brancusi would have developed had he returned to Romania from Paris. As this superb show leaves New York, might we ponder how he would have fared if, like two other Central European sculptors -- Elie Nadelman and Gaston Lachaise -- he had emigrated to America? Or, shouldnt we just count our blessings that whenever we want, we can find wonderful groupings of Brancusis art in museums in New York, Philadelphia and Washington, D.C.?