The Wealth of Nations by Part 4 Chapter 5 Page 111

First, the tax of Spain, the prohibition in Portugal of exporting gold and silver, and the vigilant police which watches over the execution of those laws, must, in two very poor countries, which between them import annually upwards of six millions sterling, operate not only more directly but much more forcibly in reducing the value of those metals there than the corn laws can do in Great Britain. And, secondly, this bad policy is not in those countries counterbalanced by the general liberty and security of the people. Industry is there neither free nor secure, and the civil and ecclesiastical governments of both Spain and Portugal are such as would alone be sufficient to perpetuate their present state of poverty, even though their regulations of commerce were as wise as the greater part of them are absurd and foolish.