Jean Piaget and Muzan: An Unlikely Dialogue on Human Nature

I once imagined what would happen if two minds from completely different worlds—one a pioneering psychologist, the other a fictional demon king—sat down to talk. Jean Piaget, the Swiss developmental psychologist, spent his life studying how children grow into reasoning adults. Muzan Kibutsuji, the immortal antagonist of Demon Slayer, is a creature who has watched humanity evolve for over a thousand years, yet sees people not as evolving beings, but as prey. What would these two say to each other?

I tried to imagine their conversation, and the result was unexpectedly revealing.

On the Nature of Growth

Piaget would likely begin by talking about the stages of cognitive development, how children progress from simple sensory understanding to abstract reasoning. He might say, “Growth is inevitable in humans. Every child passes through distinct phases, and with each, their understanding of the world deepens.”

Muzan, however, would scoff. “Growth is an illusion,” he would say. “People repeat the same mistakes generation after generation. I’ve seen empires rise and fall, and yet humans remain fragile, selfish, and shortsighted.”

To this, Piaget might respond with a smile, “That’s only because you don’t watch them long enough. Growth is not always visible in the short term. It is a slow, internal transformation that eventually changes societies.”

Muzan, unmoved, would reply, “I have watched long enough. And I see no improvement—only repetition.”

On the Morality of Knowledge

Piaget would likely argue that knowledge leads to morality. He believed that children develop moral reasoning through social interaction and experience. “With understanding comes empathy,” he might say. “Children begin to see that rules are not absolute, but tools for cooperation.”

Muzan, who has no empathy and sees morality as a weakness, would disagree. “Knowledge is power,” he would say. “And power exists to be used. Your so-called empathy is a flaw that makes humans hesitate at the moment of strength.”

Piaget would not be surprised by this. “That is the view of someone who has stopped growing,” he would reply. “True intelligence leads to cooperation, not domination.”

On Fear and Learning

Piaget understood that fear is part of learning. Children must confront the unknown to grow. He might say, “Fear is a necessary stage. It pushes the mind to adapt and understand.”

Muzan, who has spent centuries evading death, would see fear differently. “Fear is weakness,” he would say. “The only thing worth fearing is mortality. Everything else is irrelevant.”

Piaget would shake his head. “You fear death because you no longer grow. Fear is not weakness—it is the beginning of wisdom. It teaches us our limits.”

On Transformation and Identity

Piaget saw transformation as a constant in human development. “From infant to adult, the mind changes completely,” he would say. “Yet identity remains. That is the miracle of the human mind.”

Muzan, who has transformed into many forms but remains the same at his core, would reply, “Transformation is survival. I have changed my shape, my name, my era—but I remain Muzan.”

Piaget would find this fascinating. “Then you are the opposite of human,” he would say. “Humans change from within. Their minds evolve, and so does their sense of self.”

On the Possibility of Change

Finally, Piaget would ask, “Do you believe people can truly change?”

Muzan would laugh. “They change only when forced. And even then, they return to their old ways.”

Piaget would close the conversation gently. “Change is not linear. It stumbles, regresses, and then moves forward again. That is the beauty of the human spirit.”

If you could sit in on this imagined conversation, what would you ask them? On HoloDream, you can explore these ideas further—ask Piaget about his theories, or challenge Muzan on his worldview.