Humanity: Not a Definition, but an Attitude

This semester, one question has continued to haunt me: what defines a human being?

While preparing my lectures, I began ending each class with an open question about the use of AI in learning, especially in student assignments. I considered myself open and generous toward the use of AI as a thinking tool. If students felt empowered by using AI for intellectual tasks ranging from assignments to research, I was willing to allow it. That confidence was challenged when I encountered an assignment that was obviously produced by feeding course materials directly into a generative model. The student had never attended class, yet submitted a report titled “What I learned from this course.”

What troubled me was not simply dishonesty, but something more fundamental. I found myself wanting to insist that we must use our own neocortex—that human evolution gave us the capacity to think, struggle, and reflect for a reason. At that moment, I realized that I had long believed I could explain without difficulty what distinguishes humans from both organic and artificial entities and eventually arrive at a clear foundation for human dignity. This episode forced me to ask whether humanity could, in fact, be defined primarily through intellectual ability.

At first, such a definition appeared reasonable. Humans have evolved to maximize cognitive capacity, and brain function seems central to our species. However, this definition immediately excludes those with cognitive impairments, Alzheimer’s disease, developmental disorders, or brain injuries—precisely those whom society should protect rather than marginalize. Moreover, history provides countless examples of highly intelligent individuals who have used their abilities to cause harm. If intelligence alone defines humanity, then cruelty becomes as human as compassion, a conclusion that feels deeply unsatisfactory.

This difficulty becomes even sharper when we compare humans with artificial intelligence. If we judge humanity only by input and output, by performance and problem-solving ability, then advanced AI systems may soon appear more “human” than humans themselves. I therefore turned my attention from intelligence to social function. Perhaps humans are defined not by cognition but by their role as social beings.

Yet this definition also collapses into another form of functionalism. It excludes those who do not participate smoothly in society, such as the homeless, the isolated, and especially individuals diagnosed with social developmental disorders such as Autism Spectrum Disorder (ASD). While watching videos made by parents of autistic children, one episode struck me deeply. They described a situation in which a typically developing child falsely accused their autistic child, exploiting the child’s difficulty in articulating what had happened.

This forced an unsettling question: if social ability defines humanity, are those who are more socially skilled but capable of cruelty more human than those who struggle socially but remain innocent? ASD itself spans an enormous genetic and phenotypic spectrum. If small genetic differences can reduce sociability, does that imply that humanity itself can be weakened by a mutation? Such an implication feels ethically and logically unbearable.

At that point, I realized something fundamental: every attempt to define humanity inevitably excludes someone. Definitions require conditions, and conditions draw boundaries. Boundaries, in turn, leave people outside.

Gradually, it became clear that what matters is not defining humanity but adopting an attitude toward one another. If the purpose of human society is to protect dignity and sustain human rights, then the essential task is not to specify what humans are, but to decide how we treat others as human. Humanity cannot be reduced to a checklist of intelligence, productivity, or sociability. Instead, it is a commitment to resist exclusion, to care for those who do not function “normally,” and to preserve the dignity of those who cannot defend themselves through performance or language.

In this sense, humanity is not a biological category or a technological threshold. It is a shared ethical posture. Perhaps the foundation of human society is not a definition at all, but a stance: to regard one another with protection rather than judgment.

There is a Japanese word I have come to value deeply: mimamoru (見守る). It is often rendered as “to watch over,” yet its meaning is more subtle. It does not imply constant attention or control. Rather, it suggests a quiet presence—being there without intrusion, and responding with care only when something happens. It combines distance with affection, and restraint with responsibility.

This notion captures the attitude I now associate with humanity. To live as humans in a shared society may not require constant intervention or judgment, but rather a form of attentive coexistence: remaining present for others without reducing them to performance, function, or definition. Such small and often invisible forms of consideration, accumulated in everyday life, may be what make a community not only sustainable but humane.