The nature of ownership
Tibor Machan has related to me "Wittgenstein's wonderful little exposition on the nature of ownership."
It is related by Norman Malcolm in the following story about him in which ownership is spelled out very instructively: "When in very good spirits he would jest in a delightful manner. This took the form of deliberately absurd or extravagant remarks uttered in a tone, and with the mien, of affected seriousness. On one walk he 'gave' me each tree that we passed, with the reservation that I was not to cut it down or do anything to it, or prevent the previous owners from doing anything to it: with those reservations they were henceforth mine." (Norman Malcolm, Ludwig Wittgenstein, A Memoir [London: Van Nostrand Rinehold Co., 1070], pp. 31-32.)