Point III. On Law Founded on Presumption

I. Notion. A law is said to be founded on presumption when the legislator passed it because he presumes something. Furthermore, presumption is a probable conjecture about an uncertain matter; one kind is presumption of law, which is established by the law itself; another is presumption of man, which is conjectured by a judge (can. 1825, § 1). Presumption of law is either presumption of law simply, or presumption of law and by law (can. 1825, § 2). Against presumption of law simply, both direct and indirect proof is admitted; against presumption of law and by law, only indirect proof is admitted, that is, against the fact which is the foundation of the presumption (can. 1826).

II. Obligation of a law founded on presumption. A law founded on presumption obliges or does not oblige according as that which is presumed exists or does not exist, in other words, according as the presumption is true or false. The reason is that the foundation of the law stands or falls with the truth of the thing presumed. The same must be said about a sentence of a judge founded on presumption; a sentence of this sort, if that which is presumed is false, of itself does not oblige; but by accident, namely by reason of avoiding scandal or preserving order, it can oblige (St. Alphonsus, I, 100, at the end; Homo Apostolicus, tr. 2, n. 26).

Corollary. "If in judgment it has falsely been proved that your animal caused damage, then you are not held to pay the penalty; and once a sentence has been passed that you pay, although externally, so that scandal may be avoided, you are held to pay, nevertheless you can secretly make compensation for yourself" (St. Alphonsus, Homo Apostolicus, loc. cit.).