from The Return of the King, The Last Debate
For into the midst of all these policies comes
the Ring of Power, the foundation of
Barad-dur, and the hope of Sauron. 'Concerning this thing, my lords, you now all know enough for the understanding of our plight, and of Sauron's. If he regains it, your valour is vain, and his victory will be swift and complete: so complete that none can foresee the end of it while this world lasts. If it is destroyed, then he will fall; and his fall will be so low that none can foresee his arising ever again. For he will lose the best part of the strength that was native to him in his beginning, and all that was made or begun with that power will crumble, and he will be maimed for ever, becoming a mere spirit of malice that gnaws itself in
the shadows, but cannot again grow or take shape. And so a great evil of this world will be removed.
'Other evils there are that may come; for Sauron is himself but a servant or emissary. Yet it is not our part to master all the tides of the world, but to do what is in us for the succour of those years wherein we are set, uprooting the evil in the
fields that we know, so that those who live after may have clean earth to till. What weather they shall have is not ours to rule.