"Do you think tomorrow's weather is already determined?"
Haru asked abruptly. Ren and Simon looked up.
"Following the laws of physics, in principle, yes," Ren answered.
"So the future is determined?"
"That's the problem of determinism," Simon interrupted. "In classical physics, once initial conditions are set, the future is uniquely determined."
Ren supplemented. "There's a thought experiment called Laplace's demon."
"A demon?"
"If there were a being that knew the position and momentum of every particle in the universe, it could perfectly calculate the future and past."
Haru was confused. "So all our choices are predetermined?"
"Deterministically, yes," Ren said. "The brain also follows physical laws."
"But," Simon raised a finger. "Quantum mechanics is different."
"Quantum mechanics?"
"At the quantum level, you can only predict probabilistically. There's inherent uncertainty."
Ren said cautiously. "Whether that becomes the basis for free will is debatable."
"Quantum randomness and free will might be separate issues."
Haru held their head. "So is the future determined or not?"
Simon laughed. "Both might be correct."
"What do you mean?"
"It's a matter of perspective. From God's perspective, it might be determined. But from our perspective, it's open."
Ren said philosophically. "What matters is that epistemologically, the future is uncertain."
"Epistemologically?"
"We cannot completely know the future. So practically, the future is open."
Haru felt a bit relieved. "So the future can be rewritten?"
"The expression 'rewrite' is interesting," Simon thought. "The future hasn't been written yet, so you don't rewrite it, you write it."
"But possibilities have constraints," Ren said realistically.
"For example?"
"I can't go to Mars today. There are technical and physical constraints."
Simon added. "Social and economic constraints too."
"So the future isn't completely free."
"Right. You choose from limited possibilities."
Ren organized. "The future is directed by the past and present. But not determined."
"Difference between direction and determination?"
"Direction only shows tendency. Determination fixes the result."
Haru gave an example. "Like a river's current? You ride the flow, but decide how to swim."
"Good metaphor," Simon acknowledged.
"Selecting the future rather than rewriting it."
Ren thought deeply. "Actually, the word 'rewrite' has an assumption."
"Assumption?"
"The assumption that there's an already written future. But the future doesn't exist yet."
Simon said philosophically. "Time is creative. The future is generated by present actions."
"That's Bergson's 'duration.'"
Haru's eyes sparkled. "So we're creators of the future?"
"In a sense. But you can't create everything alone."
"Others, society, nature all shape the future too."
Ren concluded. "The future emerges from the interaction of many forces."
"Within that, exercising your own power is freedom."
Haru took a deep breath. "The future can't be rewritten, but we can write into it."
"And there's always room to write," Simon smiled.
"That's hope."
The three looked up at the sky. The blank page called the future continues to be born in this very moment.