NOTHING can prepare a visitor for the shock of seeing the ancient Mesopotamian art that goes on view this Sunday at the Sackler Gallery.

These 32 ornaments, plaques, seals, statuettes, statues and stelae are the cream of the unmatched collection of the Louvre Museum in Paris. They're literally as old as history, contemporary with the birth of writing more than 5,000 years ago. Many are the type specimens, the finest examples known, used to illustrate textbooks and encyclopedias.

They've never been in America before and are not likely to ever be seen here again. The Sackler was able to borrow them briefly while the Louvre refurbishes its Department of Antiquities.

Simply to stand near these things, to be in touch with time out of mind, inspires awe. Even more awesome is the self-evident fact that, old as these objects are, the artistic tradition behind them is older still. These creations are the work of masters who learned from masters who were taught by masters.

They show the timelessness of art to be no cliche but simple truth. Some of these enchanting pieces might have been carved yesterday . . . or tomorrow. They speak to us not only from the dawn of history but from the beginnings of style: These works seem as Oriental, Indian and African as Eastern, as Greco-Roman as Sumerian. The head of a Syrian statuette of about 2400 B.C. looks for all the world like a perky Dutch girl wearing traditional headdress. In many cases these carvings, laboriously done with bronze and stone tools, are as subtle and skillful as the work of any medieval or modern artist. Another cliche they prove is that only beauty lasts.

They were carved during a period when the divine right of rulers was shading toward the divinity of kings. Most heavily represented in the collection, by chance of preservation and excavation, is a prince named Gudea, who governed an unknown expanse of Mesopotamia for about a decade around 2120 B.C. Essentially all we know about him is what he says about himself in the inscriptions on his statues and temple carvings.

Gudea, like virtually every later king, tyrant and president, says he was pious and fair and diligent, a strong war leader, a gentle husbander of his lands and a kind encourager of his people. Like Shelley's Ozymandias, all of Gudea's piety, pride, pomp and circumstance was buried in obscurity beneath the sands of time.

He was resurrected by French archaeologists who carried the statues home during the 19th century, sometimes with and often without the permission of whatever governments were in authority during that typically turbulent period in the lands between the Tigris and Euphrates. From these inscriptions and others it has been possible to piece together fragmentary and tantalizing sketches of the history of the wellspring of what we are pleased to call Western Civilization. It is a tale of sound and fury, not unlike the evening news.

The representations of Gudea are so lifelike and consistent that one cannot but believe that we're seeing the face of the man himself, a good man, gazing at us warm and wise across all those centuries. The archaeologists say no, they're just idealized images, but if they're not likenesses they're certainly lifenesses. Hail, Gudea, king of kings!

WHEN KINGSHIP DESCENDED FROM HEAVEN: Masterpieces of Mesopotamian Art from the Louvre -- Sunday through Aug. 9 at the Sackler Gallery, 1050 Independence Ave. SW. Open 10 to 5:30 daily. Metro: Smithsonian.