2639. Just Taxes.—Tax laws, like other laws, must be just; that is, they must be made by lawful authority and must promote the common good (see 285). The common good requires that taxes be not imposed except for just reasons, and that there be a fair distribution of the burden.
(a) Just reasons are those of public utility or necessity. A tax would be unjust, if it were levied for unjust or unnecessary purposes.
(b) Fair distribution requires that citizens be assessed according to their ability to pay (sacrifices for the public good, special benefits from the use of a tax fund, etc.).
2640. Obligation to Pay Taxes.—The obligation in conscience of just tax laws is admitted by all Catholic authorities.
(a) The teaching of Scripture is quite clear, since Our Lord, in answer to the question whether it were lawful to pay tribute to Caesar, replied: “Render to Caesar the things that are Caesar’s” (Matt., xxii. 17-21); and St. Paul teaches: “Be subject of necessity, not only for wrath, but also for conscience’ sake. Render therefore to all men their due, tribute to whom tribute is due, custom to whom custom” (Rom., xiii. 5, 6).
(b) Reason too shows the need of obligation in conscience, for, unless these laws oblige thus, the common good will suffer through lack of money needed for public purposes, and some individuals will be unjustly burdened and others unjustly favored.
2641. Quality of the Obligation.—There are various opinions about the quality of the obligation in conscience of taxation laws.
(a) Thus, according to one opinion they oblige in conscience and under sin, that is, as preceptive laws (see 561 sqq.). For the natural law and justice require that the members of society contribute the necessaries to the social body organized for their benefit, or that the people live up to their implicit contract with their government by giving compensation for the services they receive.
(b) According to another opinion tax laws oblige in conscience only under penalty, that is, as penal laws. The arguments for this view are, first, the sufficiency of the penal obligation (i.e., the heavy fines imposed) for the attainment of the laws’ purpose, and, secondly, the common opinion of citizens that they commit no sin by merely evading payment of taxes. Furthermore, it is added that, if these laws were preceptive, conscientious citizens would be under a great disadvantage, for they would be placed in the dilemma of either acting against their conscience and committing sin or of paying more than their due on account of the neglect of tax dues by citizens who are not conscientious.
(c) According to a third opinion distinction has to be made between different cases. Thus, some held that laws on direct taxes are preceptive and laws on indirect taxes merely penal, while others say that the kind of obligation depends on the will of the lawgiver, and that tax laws that are preceptive in one country may be only penal in another. If tax laws are merely penal, there is no obligation of restitution, but there is an obligation of payment and of penalty after sentence.