From the Jesus of Nazareth in Chapter Seven, Pope Benedict XVI takes up the story of the Good Samaritan. (p 197)
And now the Samaritan enters the stage. What will he do? He does not ask how far his obligations of solidarity extend. Nor does he ask about the merits required for eternal life. Something else happens: His heart is wrenched open. The Gospel uses the word that in Hebrew had originally referred to the mother’s womb and maternal care. Seeing this man in such a state is a blow that strikes him “viscerally,” touching his soul. “He had compassion” – that is how we translate the text today, diminishing its original vitality. Struck in his soul by the lightning flash of mercy, he himself now becomes a neighbor, heedless of any question or danger. The burden of the question thus shifts here. The issue is no longer which other person is a neighbor to me or not. The question is about me. I have to become the neighbor, and when I do, the other person counts for me “as myself.” (my emphasis)
If the question had been “Is the Samaritan my neighbor, too?” the answer would have been a pretty clear-cut no given the situation at the time. But Jesus now turns the whole matter on its head: The Samaritan, the foreigner, makes himself the neighbor and shows me that I have to learn to be a neighbor deep within and that I already have the answer in myself. I have to become like someone in love, someone whose heart is open to being shaken up by another’s need. Then I find my neighbor, or – better – then I am found by him.
Jesus of Nazareth by Pope Benedict XVI