FOTR, Book 2, Chapter 2, The Council of Elrond

Boromir is arguing for using the Ring against Sauron instead of hiding it or destroying it.

'I do not understand all this,' he said. `Saruman is a traitor, but did he not have a glimpse of wisdom? Why do you speak ever of hiding and destroying? Why should we not think that the Great Ring has come into our hands to serve us in the very hour of need? Wielding it the Free Lords of the Free may surely defeat the Enemy. That is what he most fears, I deem.