I just finished watching Dune: Part 2 a second time, and in the rewatch I'm seeing a lot more meaning behind everything Paul says after he drinks the Water of Life. I'm wondering how detailed his visions of the future are.
Can he foresee every word in every conversation? Does he know exactly how his fight with Feyd Rautha will play out before it begins, down to exactly what strikes will be attempted?
Paul explains to Stilgar exactly how detailed his foreseeing is in the moments immediately following his blinding by the stone burner:
"None of us has eyes," Paul said. "They have taken my eyes, as well, but not my vision. I can see you standing there, a dirty wall within touching distance on your left. Now wait bravely. Stilgar comes with our friends."
The thwock-thwock of many 'thopters grew louder all around. There was the sound of hurrying feet. Paul watched his friends come, matching their sounds to his oracular vision.
"Stilgar!" Paul shouted, waving an arm. "Over here!"
"Thanks to Shai-hulud," Stilgar cried, running up to Paul. "You're not..." In the sudden silence, Paul's vision showed him Stilgar staring with an expression of agony at the ruined eyes of his friend and Emperor. "Oh, m'Lord," Stilgar groaned. "Usul... Usul... Usul..."
"What of the stone burner?" one of the newcomers shouted.
"It's ended," Paul said, raising his voice. He gestured. "Get up there now and rescue the ones who were closest to it. Put up barriers. Lively now!" He turned back to Stilgar.
"Do you see, m'Lord?" Stilgar asked, wonder in his tone. "How can you see?"
For answer, Paul put a finger out to touch Stilgar's cheek above the stillsuit mouthcap, felt tears. "You need give no moisture to me, old friend," Paul said. "I am not dead."
"But your eyes!"
"They've blinded my body, but not my vision," Paul said. "Ah, Stil, I live in an apocalyptic dream. My steps fit into it so precisely that I fear most of all I will grow bored reliving the thing so exactly."
"Usul, I don't, I don't..."
"Don't try to understand it. Accept it. I am in the world beyond this world here. For me, they are the same. I need no hand to guide me. I see every movement all around me. I see every expression of your face. I have no eyes, yet I see."
Dune Messiah chapter 19
As Valorum notes, Paul's prescience is not without limits; there are definitely things he cannot foresee. Paul tries to explain to Stilgar the limits of prescience, which include simply not being able to accept what his foreseeing reveals and that foresight can reveal things which are true but not consistent:
Paul said. He steepled his hands in front of him. "But it'd be just as correct to say it's heaven speaking to us, that being able to read the future is a harmonious act of man’s being. In other words, prediction is a natural consequence in the wave of the present. It wears the guise of nature, you see.
But such powers cannot be used from an attitude that prestates aims and purposes. Does a chip caught in the wave say where it's going? There's no cause and effect in the oracle. Causes become occasions of convections and confluences, places where the currents meet. Accepting prescience, you fill your being with concepts repugnant to the intellect. Your intellectual consciousness, therefore, rejects them. In rejecting, intellect becomes a part of the processes, and is subjugated."
"You cannot do it?" Stilgar asked.
"Were I to seek Tupile with prescience," Paul said, speaking directly to Irulan, "this might hide Tupile."
"Chaos!" Irulan protested. "It has no... no... consistency."
"I did say it obeys no Natural Law," Paul said.
"Then there are limits to what you can see or do with your powers?" Irulan asked.
Before Paul could answer, Alia said: "Dear Irulan, prescience has no limits.
Not consistent? Consistency isn't a necessary aspect of the universe."
Dune Messiah chapter 6
But when his prescience works he can see everything that his eyes could, know every word and gesture that is going to happen:
"Who says I'm blind?" Paul demanded. He faced the gallery. "You, Rajifiri? I see you're wearing gold today, and that blue shirt beneath it which still has dust on it from the streets. You always were untidy."
Rajifiri made a warding gesture, three fingers against evil.
"Point those fingers at yourself!" Paul shouted. "We know where the evil is!" He turned back to Korba. "There's guilt on your face, Korba."
"Not my guilt! I may've associated with the guilty, but no..." He broke off, shot a frightened look at the gallery.
Taking her cue from Paul, Alia arose, stepped down to the floor of the chamber, advanced to the edge of Korba's table. From a range of less than a meter, she stared down at him, silent and intimidating.
Korba cowered under the burden of eyes. He fidgeted, shot anxious glances at the gallery.
"Whose eyes do you seek up there?" Paul asked.
"You cannot see!" Korba blurted.
Paul put down a momentary feeling of pity for Korba. The man lay trapped in the vision's snare as securely as any of those present. He played a part, no more.
"I don't need eyes to see you," Paul said. And he began describing Korba, every movement, every twitch, every alarmed and pleading look at the gallery.
Dune Messiah chapter 20
