Article — Prümmer, Manuale Theologiae Moralis
Article II. On The Finding Of A Lost Thing
48.
48. Preliminary Note. The finding of a lost thing, although it is not properly a species of occupation, nevertheless can be reduced to it. But a lost thing differs from treasure in two ways: a) because it has not been hidden; b) because it does not belong to no one, but still has an owner, although here and now unknown.
Concerning finding we shall treat 1. according to natural law, and 2. according to the statutes of certain civil laws.