サピエンス全史 文明の構造と人類の幸福

For millions of years, our ancestors, the various species of humans, were insignificant creatures, no more impactful on the world than gorillas or jellyfish. They huddled in the middle of the food chain, often scavengers, their existence a fleeting whisper in the vastness of time. Yet, a peculiar transformation began around 70,000 years ago, an event known as the Cognitive Revolution. It was then that *Homo sapiens* developed a unique capacity: the ability to create and believe in fictions, in imagined realities. This was not merely gossip, though that too played a crucial role in forming larger, more cohesive groups. Instead, it was the power to conceive of things that do not physically exist - gods, nations, money, human rights - and to collectively believe in them. This shared mythology allowed for unprecedented, flexible cooperation among vast numbers of strangers, a feat impossible for any other animal. It was this singular ability, more than any physical prowess, that propelled *Homo sapiens* to the top of the food chain, leading to the rapid expansion across continents and, often, the extinction of other human species and megafauna.

Then came the Agricultural Revolution, a profound shift around 12,000 years ago. Humans began to abandon their hunter-gatherer ways, settling down to cultivate crops like wheat and rice, and to domesticate animals such as sheep and chickens. This era, however, was not the clear step forward it is often imagined to be; in many ways, it was history's greatest fraud. While it allowed for an exponential increase in population and the accumulation of more food per unit area, the lives of individual humans, and certainly of the domesticated animals, often became harder. Farmers toiled longer hours, their diets became less varied and often less nutritious, and they were plagued by new diseases in their crowded settlements. The future, once an immediate concern for the next hunt, now brought anxieties about harvests, droughts, and pests. The evolutionary success of the species came at the cost of individual well-being, a pattern that would echo throughout history.

As millennia passed, the fragmented pockets of humanity began to converge, driven by the forces of money, empires, and universal religions. These were all powerful imagined orders, shared myths that allowed for even larger-scale cooperation and the unification of humankind. Money, a universal medium of trust, enabled trade between strangers with vastly different beliefs. Empires imposed common laws and cultures over diverse populations. Religions, from polytheism to the unifying narratives of monotheism, offered shared values and a sense of belonging that transcended tribal loyalties. This gradual process created ever-larger, more complex societies, eroding local distinctions and weaving a global tapestry of interconnectedness, even as it often brought conflict and oppression.

The most recent and perhaps most impactful transformation arrived with the Scientific Revolution, beginning roughly 500 years ago. Its defining characteristic was not the acquisition of knowledge itself, but the discovery of ignorance - the radical admission that humans do not know the answers to life's most important questions. This willingness to admit what was unknown fueled an insatiable curiosity and a systematic pursuit of new knowledge through observation and mathematics, rather than relying solely on traditional stories or religious texts. This revolution, intertwined with the rise of capitalism and imperialism, unleashed an unprecedented surge in human power and influence, transforming the world at an accelerating pace. It has given *Homo sapiens* god-like abilities, allowing us to manipulate our environment and even ourselves on a scale unimaginable to our ancestors.

Today, we stand at a precipice, empowered by science and technology to reshape life itself, to engineer our own successors, whether through biological manipulation, cybernetics, or artificial intelligence. We are on the verge of overcoming natural selection, of designing our future. Yet, despite this immense power, a fundamental question lingers: are we any happier? The progress has been undeniable, the control over our environment almost absolute, but the narrative of individual suffering, born in the Agricultural Revolution, has not entirely faded. As we contemplate the end of *Homo sapiens* as we know it and the dawn of a new era, we are left to ponder what we truly want, and whether we even know what it is we should want.