Opposition to an industrial system based upon _laissez faire_ would have been even greater during the seventies and eighties if it had not been for two sources of national wealth--the public lands and the supplies of lumber, ore, coal and similar gifts of nature. When the supply of land in the West was substantially unlimited, a sufficient part of the population could relieve its economic distresses by migrating, as multitudes did. Such huge stores of natural wealth were being discovered that there seemed to be no end to them. But in the late eighties when the best public lands were nearly exhausted and the need of more careful husbanding of the national resources became apparent to far-sighted men, advanced thinkers began to question the validity of an economic theory which allowed quite so much freedom to individuals. For the time, however, such questions did not arise in the minds of the masses. As the _laissez faire_ doctrine underlay the problem of the relation between government and industry, so the quantity theory of money was fundamental in the monetary question. According to the quantity theory, money is like any other commodity in that its value rises and falls with variations in the supply and demand for it. Suppose, for example, that a given community is entirely isolated from the rest of the world. It possesses precisely enough pieces of money to satisfy the needs of its people. Suddenly the number of pieces is doubled. The supply is twice as great as business requires. If no new elements enter into the situation, the value of each piece becomes half as great as before, its purchasing power is cut in two and prices double.[2] A bushel of potatoes that formerly sold for a dollar now sells at two dollars. A farmer who has mortgaged his farm for $1,000 and who relies upon his sales of potatoes to pay off his debt is highly benefited by the change, while the creditor is correspondingly harmed. The debtor is obliged to raise only half as many potatoes; the creditor receives money that buys half the commodities that could have been purchased with his money at the time of the loan. On the other hand, suppose the number of pieces of money is instantly halved and all other factors continue unchanged. There is now twice as great a demand for each piece, it becomes more desirable and will purchase more goods. Prices, that is to say, go down. Dollar potatoes now sell for fifty cents. The debtor farmer must grow twice as many potatoes as he had contemplated; the creditor finds that he receives money that has doubled in purchasing power.