The French philosopher Simone Weil brought out some amazing insights on divine love based on this parable.
She notes that Jesus does not describe good neighbours as "loving" or "charitable", but "just". There is no distinction between justice and love. Greek justice occurs when two parties of equal strength come to an agreement. Supernatural justice occurs when an unequal relationship is treated equal by the stronger party - that is, the stronger party treats the weaker as his equal.
This is what the Samaritan did. Others walked by him, and saw an anonymous lump of flesh - they did not see a person. The Samaritan could not see the victim's humanity either, but he took that humanity on faith and acted lovingly towards the victim. Weil says that in this way, "Love shows us what is invisible."
The love of the Samaritan is not creturely love, it is divine love. She has an odd idea about Creation which I cannot agree with it, but it can deepen our understanding of love, so here it is:
God and His creatures are less than God alone. Creation was an act of loving renunciation - "He emptied a part of His being from Himself; that is why John says that the lamb had been slain from the beginning of the world."
When we love our neighbour, we are replicating God's love for Creation. We renounce a part of ourself. No person can love his neighbour. (I distinguish neighbour from friend, relative, beloved, etc.) God gives us that love.
"Only God, present in us, can really look at the afflicted with a look differing from what we give to ‘things’, can listen to their voice as we listen to spoken words. The love of our neighbour is the love which comes down from God to man."