Amicorum sunt communia omnia.
(M.Tullius Cicero, Greek Proverb Quoted in De Officiis 1.16.51)

Friends hold all things in common.

Pron= ah-mee-KOH-room soont kohm-MOO-nee-ah OHM-nee-ah.

Comment: What kinds of things do friends hold in common? Modern
Americans don't subscribe to the notion that everything they own also
belongs to their friends. Certainly among close friends there might
be a sharing of possessions, but even then, it is very clear who the
owner is, and who the borrower is, and many a friendship has
deteriorated over how the possession was treated between them.

Romans, certainly wealthy Romans, owned many possessions, and they did
among their friends share and enjoy hospitality of home and property,
but they did not have a notion of communism or the common ownership of
possessions.

Cicero not only quotes this Greek proverb, but he cites in this same
passage an example from Ennius. Ennius offers the metaphor of a man
who helps another who is lost to find his way. He observes that if
the helper lights the lost man's lamp, his own lamp (and really light)
is not diminished by giving flame to the other's lamp.

Certainly the one man could say--here, friend, let me give you my
light. And the other would gladly take and receive the light from the
friendly man's lamp. And yet, no one would really want to claim that
the friendly man "owned" the flame. And yet, he did have a lamp; he
did have fire; he did share the flame and helped the other find his
way. He could also have refused to share something that he really did
not own.

What kinds of things do we hold in common as human beings that really
cannot be diminished by sharing them and by giving them away?
Further, what kinds of things do we hold in common as human beings,
that we can share, but which we refuse to share? Do we have light
that we are not sharing?