LotR -- Book 2 - Chapter 10 - The Breaking of the Fellowship

[Encaitare]

I just found this line interesting:

"It is by our own folly that the Enemy will defeat us."

Boromir says this to Frodo when he refuses to give him the Ring. Boromir is under the Ring's influence, but it surely just reveals the doubts he has had all along. He still cannot accept that the only hope is to destroy that which he would seek to take for his own.

However, Boromir is partly right. If they had demonstrated "folly" and decided to try and use the Ring against Sauron, Sauron might have fallen, but could have risen once more while the world of Men destroyed itself fighting over who would keep the Ring. Frodo himself was nearly defeated; he eventually gave in to the Ring. Now, he had gone through so much torment that it's not really fair to call this act "folly," but the world could have been defeated had Gollum not done his part in finishing the job.