Boromir. Here we have the two brothers and their actions
contrasted. Boromir "delighted in arms" and sees the military
solution (using the Ring for victory. Faramir "the wizard's pupil"
understands the importance of not using the Ring and sending it to Mt.
Doom. He states twice that he would not use it "even if it was lying by
the side of the road". So Faramir and Boromir and their different actions
are another literary device to compare the favored son (who will fail) and the
unfavored son (who will triumph using aspects of his character that were
previously unadmired).
I really enjoyed the whole post by NZ Strider
too!