The funds or sources of revenue which peculiarly belong to the sovereign or commonwealth consist either in stock or in land; but being quite insufficient to meet the public expenditure they are supplemented by taxation. Every tax is finally paid from rent, profit or wages, or from all of them indifferently; and the chief principle to be observed in taxation is, that the subjects of the State ought to contribute towards the support of the government, as nearly as possible, in proportion to their respective abilities--that is, in proportion to the revenue which they respectively enjoy under the protection of the State. The tax which each individual is bound to pay ought to be certain and not arbitrary; every tax ought to be levied at the time or in the manner in which it is most likely to be convenient for the contributor to pay it; and finally, every tax ought to be so contrived as to take out and to keep out of the pockets of the people as little as possible over and above what it brings into the public treasury of the State.