It has never been a question of whether to restore the Parthenon, the ancient temple ruin of Acropolis, an internationally recognized scholar on antiquities said Thursday. The question is which historic period architects and historians can agree upon to restore it to.

Eugene N. Borza, a professor at Pennsylvania State University, delivered the annual David P. Gardner Lecture this week in the University of Utah Fine Arts Auditorium, addressing the topic, "That Old Ruin, the Parthenon."His first visit to the ancient temple in Greece in 1957 left him with a comfortable feeling. The Athenian temple "immediately seemed familiar, like an old friend." Borza has since returned on several occasions to further document the restoration process.

That restoration continues to intrigue Borza because of the debate over the style of which period of history the Parthenon should be restored to. Since its creation in the 5th century B.C., the Parthenon has undergone several utilitarian and structural changes.

The original structure was created as a commemoration to Imperial Athens and dedicated as a temple to the Virgin Athena. By the 13th century A.D., crusaders entered into the eastern Mediterranean and converted the temple into a Catholic church. Two centuries later, Turks overtook Athens and converted the Parthenon into a mosque.

In 1687, Turks were attacked by the Venetian army and surrendered Athens. A short seven months later, the city was abandoned, leaving behind severe damage to the temple and its surrounding structures on the Athenian Acropolis.

Through the years, the Parthenon has been nearly destroyed in military attacks and by the slow removal of stone by foreigners and local inhabitants. With the establishment of Greek rule in the early 19th century, the decision to restore the Parthenon was immediately implemented.

Borza said the restoration process has been difficult because of the severe damage left from military action, subsequent fires, earthquakes, pollution and the 2.5 million tourists who visit Athens each year.

But the question troubling both architects and historians is deciding which of its many converted stages and historical uses the Parthenon should be returned to.

"The Parthenon has a history of more than 24 centuries," Borza said. "And they all have equal claim to its restoration. It's a continuing quest to ask ourselves what kind of relationship we want to maintain between the past and the present."