The height of the classical period, or Golden Age (c.450–400 B.C.), was the time of Pericles and Thucydides, of the great dramatists Sophocles and Euripides, and of the young Socrates. The aesthetic ideal based on the representation of human character as an expression of a divine system embodying a rational ethic and ordered reality was integral to the culture. The sculptor Polycleitus sought to arrive at a rational norm for the structure of the ideal human figure. The most magnificent original sculptures from this period are those from the temples of the Athenian acropolis. Earliest of these are theParthenon sculptures including the frieze representing the Panathenaic procession and the pedimental sculptures (Elgin Marles). The Parthenon sculptors are anonymous, but Phidias is believed to have drawn up the designs. Somewhat later in date are the sculptures of the Hephaesteum, the Erechtheum, and the Nike Balustrade.