In a contract, three things happen at once. Each person stops being an owner. Each person remains an owner. And each person becomes an owner.

An example: Anna swaps her bike for Ben’s guitar. Anna loses the bike. She gets the guitar. And she stays an owner the whole time, only of something else. It is the same for Ben.

What matters here:

No one decides alone. Anna gives the bike only because Ben gives the guitar. Ben gives the guitar only because Anna gives the bike. One will arrives at its resolve only when the other will is present.

Summary: In a contract, two decisions hang on each other. Each gives, each gets, and both remain owners.