According to Cleon Skousen, early critics of the Book of Mormon thought the Old Testament prophets could not have known that Jesus would die on a Roman cross since death by crucifixion was not supposed to have been known before the Romans. These critics counted it a serious error that Book of Mormon prophets would pretend to know how Jesus would die. However, as Dr. Hugh Nibley has pointed out, it is now known that the symbol of the cross as the means by which the Savior would die has been found in the literature of ancient times. [W. Cleon Skousen, Treasures from the Book of Mormon, Vol. 2, p. 2132]