Justice is not Healing. Healing cometh only by suffering and patience, and maketh no demand, not even for Justice. Justice worketh only within the bonds of things as they are... and therefore though Justice is itself good and desireth no further evil, it can but perpetuate the evil that was, and doth not prevent it from the bearing of fruit in sorrow.
One tiny Hobbit against all the evil the world could muster. A sane being would have given up, but Samwise burned with a magnificent madness, a glowing obsession to surmount every obstacle, to find Frodo, destroy the Ring, and cleanse Middle Earth of its festering malignancy. He knew he would try again. Fail, perhaps. And try once more. A thousand, thousand times if need be, but he would not give up the quest.
What a pity that Bilbo did not stab that vile creature, when he had a chance!' Pity? It was Pity that stayed his hand. Pity, and Mercy: not to strike without need. And he has been well rewarded, Frodo. Be sure that he took so little hurt from the evil, and escaped in the end, because he began his ownership of the Ring so. With Pity.
Eomer said, 'How is a man to judge what to do in such times?' As he has ever judged,' said Aragorn. 'Good and evil have not changed since yesteryear, nor are they one thing among Elves and another among Men. It is a man's part to discern them, as much in the Golden Wood as in his own house.