The Romans did not believe that to have a copy of an artwork was of any less value that to have the original

Polykleitos, Doryphoros (Spear-Bearer), Early Classical Period, Roman marble copy after a Greek bronze original from c. 450-440 B.C.E. (Museo Archaeologico Nazionale, Naples). Speakers: Dr. Beth Harris & Dr. Steven Zucker. Created by Beth Harris and Steven Zucker.

The Romans did not believe, as we do today, that to have a copy of an artwork was of any less value that to have the original.

Greek art certainly had a powerful influence on Roman practice; the Roman poet Horace famously said that “Greece, the captive, took her savage victor captive,” meaning that Rome (though it conquered Greece) adapted much of Greece’s cultural and artistic heritage (as well as importing many of its most famous works).

It is also true that many Romans commissioned versions of famous Greek works from earlier centuries; this is why we often have marble versions of lost Greek bronzes such as the Doryphoros by Polykleitos.

Source:Smarthistory