Rome lived upon its principal till ruin stared it in the face. Industry is the only true source of wealth, and there was no industry in Rome. By day the Ostia road was crowded with carts and muleteers, carrying to the great city the silks and spices of the East, the marble of Asia Minor, the timber of the Atlas, the grain of Africa and Egypt; and the carts brought out nothing but loads of dung. That was their return cargo.

– The Martyrdom of Man by Winwood Reade (1871)