"I wonder if there's such a thing as a perfectly rational human."
Ren said, unusually weak.
Noa was surprised. "Aren't you always logical, Ren-senpai?"
"That's why I feel the limits."
Haru showed interest. "What kind of limits?"
"Emotions get in the way," Ren admitted. "Even when I understand logically, I react emotionally."
Noa said gently. "Isn't that what makes us human?"
"But if pursuing rationality, emotions become obstacles."
Haru objected. "Really? Are emotions that much of a hindrance?"
Ren thought. "In economics, humans are assumed to act rationally."
"But actual humans are irrational."
Noa supplemented. "Behavioral economics studies that, right?"
"Yes. As Kahneman and Tversky showed, humans have cognitive biases."
Haru asked. "Cognitive bias?"
"Distortions in judgment. For example, confirmation bias. The tendency to gather only information that supports your beliefs."
"That happens," Haru laughed.
Ren continued. "Also, loss aversion. Fearing loss more than gaining."
"Sunk cost fallacy. Trying to recover what's already invested by investing more."
Noa pondered. "But these biases have reasons, right?"
"From an evolutionary psychology perspective, yes," Ren acknowledged. "They were adaptive in past environments."
"Quick judgment was advantageous for survival. Intuition was more useful than perfect logic."
Haru understood. "So emotions aren't completely bad."
"Right. The problem is that old intuitions don't always function in modern society."
Noa offered another perspective. "But without emotions, you can't make judgments either."
"What do you mean?"
"Research by neuroscientist Damasio. Patients who lost emotions couldn't even make simple decisions."
Ren was surprised. "Emotions are necessary for judgment?"
"Value judgments require emotions. What matters, what's desirable."
"Logic alone can't set goals."
Haru clapped. "So rationality and emotion aren't opposed."
"They might be cooperative," Ren reconsidered.
Noa continued. "Emotions set goals, reason finds means."
"Both are necessary."
Ren nodded deeply. "There's Simon's concept of 'bounded rationality.'"
"Bounded rationality?"
"Human rationality has limits. Information processing capacity, time, cognitive resources."
"So becoming perfectly rational is impossible."
Haru showed a relieved expression. "So it's okay not to be perfect."
"Rather, not aiming for perfection might be rational."
Noa smiled. "Efficient imperfection."
Ren organized. "Human rationality depends on context."
"Mathematical proofs require strict logic. But emotions matter in conversations with friends."
"Use them according to the situation."
Haru asked. "So how rational can we be?"
"To the extent we recognize our limits," Ren answered.
"Metacognition. Objectively viewing your own thought processes."
Noa added. "And making judgments while aware of biases."
"Can't be perfect, but can improve."
Ren smiled unusually. "Not suppressing emotions, but understanding them."
"Listening to emotional voices while adjusting with reason."
Haru concluded. "Humans can't be perfectly rational. But we can be wise."
"Wisdom is the harmony of rationality and emotion."
The three nodded quietly. Human rationality is human precisely because it has limits.