Great civilisations: Built on trade, but wary of traders

China ranked people in four groups: scholar, farmer, artisan, merchant. Shi, nong, gong, shang. The idea is old, found in the Guanzi. The scholar governs. Farmer grows food. Artisan makes things. The merchant makes nothing. He buys low, sells high and keeps the difference. So, he goes to the bottom. The first Han emperor, Gaozu, took this seriously. Sima Qian tells us he banned merchants from wearing silk and from riding in carriages. He taxed them hard. Made them look poor, even if they were rich. Then the state ran short of money.