If Boromir had misbehaved and taken the Ring for himself, would Aragorn have been ABLE to relieve him of his head?
PS: I really liked that scene from the movie as well.
-Kevin
Oh I think Aragorn was ready to act before Boromir would have been able to do anything. It takes time to master the power of the Ring, once claimed, and our Boromir was not the sharpest knife in the drawer.