Were it possible that a society should exist, in which every member would of his own accord industriously pursue the increase of national property, without waste or extravagance, the public wealth would be impaired by every species of taxation. But there never was, and unless human nature should change, there never will be such a society. In any given number of men, there always will be some who are idle, and some who are extravagant. In every society also there must be some taxes, because the necessity of supporting government and defending the State always exists. To do these on the cheapest terms is wise, and when it is considered how much men are disposed to indolence and profusion it will appear, that even if those demands did not require the whole of what could be raised, still it would be wise to carry taxation to a certain amount, and expend what should remain after providing for the support of government and the national defence, in works of public utility, such as the opening of roads and navigation. For taxes operate two ways towards the increase of national wealth. First, they stimulate industry to provide the means of payment. Secondly, they encourage economy, so far as to avoid the purchase of unnecessary things, and keep money in readiness for the tax gatherers. Experience shows, that those exertions of industry and economy grow by degrees into habit. But in order that taxation may have these good effects, the sum which every man is to pay and the period of payment, should be certain and unavoidable.