The Decalogue as an Outline of Friendship

An interesting passage in Herbert McCabe's On Aquinas (p. 55):

Of course discovering what kind of animals we are and what this implies takes a very long time and centuries of poetry and drama and critical philosophical thinking, and even then we are likely to make a lot of mistakes. That is why Aquinas thought it was very decent of God to help us out by giving us an outline of what it is to live in friendship: this is the Ten Commandments....[T]he Decalogue is part of God's summons to Israel to be his people, to share in his life and his righteousness. God is telling them that the first step to being God's people is to be human people, and that means living in friendship. This use of human means is a minimal requirement for living beyond our means, living in the divine friendship which is God.

It is, however, important to see that what is provided by such a document as the Decalogue is precisely an outline of friendship. That is to say, it draws a boundary around friendship to show where it stops: beyond these limits friendship does not exist. This is the characteristic function of law.