It may sound odd to speak of friendship as a contract, because it seems to reference an unfeeling or legalistic business model, but in the ancient world, in the pre-lawyer culture of the patriarchs, there wasn’t much of a difference. A contract was a promise; it was a vow; it was giving your word of honor; and people would swear themselves to friendship in a way that is no longer common in our culture. Establishing a relationship of voluntary commitment in this way is the purest exercise of our freedom.