Physiocracy (from the Greek for "Government of Nature") is an economic theory developed by a group of 18th century Enlightenment French economists who believed that the wealth of nations was derived solely from the value of "land agriculture" or "land development" and that agricultural products should be highly priced. Their theories originated in France and were most popular during the second half of the 18th century. Physiocracy is perhaps the first well-developed theory of economics.