Lord of the Ring Quote

Came across this quote while halfway through the trilogoy. The context is that Frodo and Sam have just come across Gollum following them on their trek to Mordor. Frodo flashes back to a conversation had before:

Deserves death! I daresay he does. Many that live deserve death. And some die that deserve life. Can you give that to them? Then be not too eager to deal out death in the name of justice, fearing for your own safety. Even the wise cannot see all ends.