Section — Wouters, Manual of Moral Theology
II. On Succession Tax
I. Notion. Succession tax is a tax which heirs must pay to the treasury from an inheritance obtained.
II. Justice of the law. The law of succession tax, considering the character of the tax, is commonly held to be just; for no reason can be assigned why the State cannot claim for itself a part of goods acquired by inheritance just as it can a part of other goods. I have said considering the character of the tax, because many judge that, in many regions, the part to be yielded to the treasury is greater than is just; but I would respond that it matters little whether taxes are imposed on goods acquired by inheritance or on other goods, provided that the taxes taken together are not greater than is just.
III. Obligation of the law. The law seems mixed, or to oblige to the act, and this even if succession tax is counted among indirect taxes. For the reasons brought forward in n. 1054 hold; nor can contrary common estimation be opposed. For the aforesaid estimation does not so much hold the law to be merely penal as the part to be assigned to the treasury to be greater than is just.
Corollary I. He who, according to what was said in n. 1055, judges that he contributes sufficiently to the common good, even if he does not declare a part, can swear with a restriction that the declaration issued by him was without reticence or less complete designation, namely by understanding silently: insofar as the omitted things had to be declared in conscience. This also applies to a promissory oath of declaring the things which he will afterwards find not yet to have been declared, or not to have been declared rightly.
Corollary II. He who swore that he had declared all things, knowingly concealing a part that had to be declared in conscience, is guilty of perjury; but he is not held afterwards to declare the concealed part, because by force of the added promissory oath he is held only to declare those things which he will afterwards find not to have been declared, or not to have been declared rightly.