'There came a turning point in the clash of the light againstthe dark.
It did not come from a flash of lightning or slash of energy blade, though there were these in plenty; it did not come from aflying kick or a surgically precise punch, though these weretraded, too.
It came as the battle shifted from the holding office to thegreat Chancellor's Podium; it came as the hydraulic lift beneaththe Podium raised it on its tower of durasteel a hundred metersand more, so that it became a laserpoint of battle flaring at thefocus of the vast emptiness of the Senate Arena; it came as theForce and the podium's controls ripped delegation pods free ofthe curving walls and made of them hammers, battering rams,catapult stones crashing and crushing against each other in arolling thunder-roar that echoed the Senate's cheers for thegalaxy's new Emperor.
It came when the avatar of light resolved into the lineageof the Jedi; when the lineage of the Jedi refined into one singleJedi.
It came when Yoda found himself alone against the dark.
In that lightning-speared tornado of feet and fists and bladesand bashing machines, his vision finally pierced the darkness thathad clouded the Force.
Finally, he saw the truth.
This truth: that he, the avatar of light, Supreme Master of the Jedi Order, the fiercest, most implacable, most devastatinglypowerful foe the darkness had ever known...just—didn't—haveit.
He'd never had it. He had lost before he started.
He had lost before he was born.
The Sith had changed. The Sith had grown, had adapted,had invested a thousand years' intensive study into every aspect of not only the Force but Jedi lore itself, in preparation for exactly this day. The Sith had remade themselves.
They had becomenew.
While the Jedi—
The Jedi had spent that same millennium training to refightthelast war.
The new Sith could not be destroyed with a lightsaber; theycould not be burned away by any torch of the Force. Thebrighter his light, the darker their shadow. How could one win awar against the dark, when war itself had become the dark's ownweapon?
He knew, at that instant, that this insight held the hope ofthe galaxy. But if he fell here, that hope would die with him.Hmmm,Yoda thought.A problem this is...' - ROTS Novelisation, CH20.
It's open to interpretation whether it is directly factually stated by the omniscient narrator, or a case of free indirect discourse, I personally see it as the latter.