The growth and development of the colonies brought forward, in succession, two practical questions. The first was, how far the interests of the colonies, as appendages to the crown, but subject, nevertheless, to an undefined parliamentary authority, could be subordinated to the interests of the trading and manufacturing classes in England. This was purely an economic question, and the answer to it in England assumed the subjection of the colonies and the validity of the mercantile system, neither of which was vigorously contested by the colonists so long as neither was rigidly enforced. But the question changed during the progress, and more especially at the close, of the French War, and then became this: How far could the interests of the colonies be subordinated to the necessities of an imperial revenue and the political policy of an empire? Hence arose the second question: What degree of autonomy could be allowed to the colonies, as integral parts of the empire, entitled to its privileges and subject to its burdens, when both were to be determined consistently with the constitutional prerogatives of the king and the supremacy of Parliament on the one side, and on the other with the natural and acquired rights of the colonies? Regarded purely as an economic question, it was a matter of indifference to the colonists whether their pockets were depleted by the enforcement of an old policy or by the adoption of a new policy. The Sugar Act of 1733, if enforced, would have produced a parliamentary tax. The Grenville Act of 1764 did no more. But the former was intended as a regulation of trade; the latter to produce a revenue. This difference of intent raised a constitutional question, and it was on this constitutional question, behind which lay the real economic question, that the patriotic party chose to fight the battle. Grenville's Act, as an external tax, produced but little; and the Stamp Act, as an internal tax, not a farthing.