nPhysiocracyfiz-i-ok′rā-si the economic doctrine of the physiocrats (François Quesnay, 1694-1744, and his followers), that society should be governed by a natural order inherent in itself, land and its products the only true source of wealth, direct taxation of land the only proper source of revenue
Chambers's Twentieth Century Dictionary
Gr. physis, nature, kratein, to rule.
This is what was meant by Physiocracy, the supremacy of the Natural Order.
"The Idea of Progress" by J. B. Bury
Free trade no less than agrarianism characterized physiocracy.