Does Finding an Unattended Object Make It Yours?

If you find a wallet on a park bench, what you first acquire is possession in the factual sense: the wallet is in your hands and you can control it. Ownership, however, is a socially recognised set of rights, including rights to exclude others, use the object and transfer it. An object being temporarily unattended does not erase the owner’s claim.

When Locke discussed the acquisition of property, his central question was how someone might form a justified claim over natural resources that were held in common and not yet possessed, especially through labour. That argument does not directly justify keeping lost property. A lost wallet is not ownerless, and losing it is not the same as abandoning it. Contemporary philosophy likewise treats property as a system of rules governing access and control, not simply as a contest over who gets hold of an object first.

The finder is therefore closer to a temporary custodian. My judgement is that finding lost property normally creates duties to protect it reasonably, look for the owner or hand it to an appropriate authority. The claim may change only if the owner genuinely abandoned the object, or if the required process has been followed and no one with a stronger right appears. Possession tells us who controls an object; ownership asks who has a justified claim to keep controlling it. They should not be confused.

https://plato.stanford.edu/entries/property/
https://www.gutenberg.org/files/7370/7370-h/7370-h.htm