These '' physiocrats '' opposed mercantilism ( a closed trading system that influenced the economic policies of most governments at the time ) , many argued that land , not the gold and silver that many kings were hoarding , was the true source of wealth .
These '' physiocrats '' opposed mercantilism ( a closed trading system that influenced the economic policies of most governments at the time ) . 
 Many argued that land , not the gold and silver that many kings were hoarding , was the true source of wealth .