They lived on the produce of the soil, not upon the profits of trade.

他们靠土地出产为生，而不是靠贸易的利润。

When the profits of trade happen to be greater than ordinary over-trading becomes a general error, both among great and small dealers.

当交易的利润恰好大于普通交易时，无论是大交易商还是小交易商，过度交易都会成为一种普遍的错误。