This Spanish commercial system was based upon two distinct principles. One was the principle of colonial exclusivism, according to which all the trade of the colonies was to be reserved to the mother country. Spain on her side undertook to furnish the colonies with all they required, shipped upon Spanish vessels; the colonies in return were to produce nothing but raw materials and articles which did not compete with the home products with which they were to be exchanged. The second principle was the mercantile doctrine which, considering as wealth itself the precious metals which are but its symbol, laid down that money ought, by every means possible, to be imported and hoarded, never exported.[4] This latter theory, the fallacy of which has long been established, resulted in the endeavour of the Spanish Hapsburgs to conserve the wealth of the country, not by the encouragement of industry, but by the increase and complexity of imposts. The former doctrine, adopted by a non-producing country which was in no position to fulfil its part in the colonial compact, led to the most disastrous consequences. While the Spanish Crown was aiming to concentrate and monopolize its colonial commerce, the prosperity of Spain itself was slowly sapped by reason of these mistaken economic theories. Owing to the lack of workmen, the increase of imposts, and the prejudice against the mechanic arts, industry was being ruined; while the increased depopulation of the realm, the mainmort of ecclesiastical lands, the majorats of the nobility and the privileges of the Mesta, brought agriculture rapidly into decay. The Spaniards, consequently, could not export the products of their manufacture to the colonies, when they did not have enough to supply their own needs. To make up for this deficiency their merchants were driven to have recourse to foreigners, to whom they lent their names in order to elude a law which forbade commerce between the colonies and traders of other nations. In return for the manufactured articles of the English, Dutch and French, and of the great commercial cities like Genoa and Hamburg, they were obliged to give their own raw materials and the products of the Indies--wool, silks, wines and dried fruits, cochineal, dye-woods, indigo and leather, and finally, indeed, ingots of gold and silver. The trade in Spain thus in time became a mere passive machine. Already in 1545 it had been found impossible to furnish in less than six years the goods demanded by the merchants of Spanish America. At the end of the seventeenth century, foreigners were supplying five-sixths of the manufactures consumed in Spain itself, and engrossed nine-tenths of that American trade which the Spaniards had sought so carefully to monopolize.[5]