The third and last duty of the sovereign commonwealth, is that of erecting and maintaining those public institutions and those public works, which though they may be in the highest degree advantageous to a great society, are, however, of such a nature that the profit could never repay the expenses to any individual or small number of individuals; and which it therefore cannot be expected that any individual or small number of individuals, should erect or maintain. (Bók 5, Kap. 1.)
Skattur er ikki revsing, men neyðugu fyri at samfelagið kann fungera, og Adam Smith vil ikki hava flatskatt, men progressivan skatt:
The rich should contribute to the public expense, not only in proportion to their revenue, but something more than in that proportion.
(...) Every tax, however, is, to the person who pays it, a badge, not of slavery, but of liberty. (Bók 5, Kap. 2.)