The Arrow of History

As trade routes, migration, and imperial expansion reach further, local customs come under real pressure to translate themselves into tools that strangers from far away can also recognize and use: coins that hold value across borders, contracts enforceable outside a single tribe's customs, calendars and scripts legible to distant trading partners, and legal rules general enough to apply beyond any one community.

This convergence does not mean human life becomes uniform or that all cultural difference disappears — Harari is careful to reject that reading. It means, more precisely, that the space of workable, self-contained cultures steadily narrows, because large-scale coordination requires a baseline of compatibility that isolated custom simply cannot provide. A single village can run perfectly well on its own local myth and unwritten tradition, but an empire needs standardized taxes, roads, and a shared administration; a genuinely global economy needs standard measures, extendable credit, and legal predictability that no local custom alone can guarantee.

The arrow of history, in Harari's phrase, does not point toward better in any straightforward moral sense — it points toward connected. Greater connectedness reliably amplifies power (empires, corporations, and states all grow more capable as they integrate), spreads ideas faster and further than isolated cultures ever could, and just as reliably spreads damage: disease, exploitation, and conflict travel the same connective tissue that ideas and trade do.

Once any two societies become genuinely linked through trade, conquest, or shared technology, Harari's larger point is that neither one remains purely itself afterward — the very act of connection changes both sides, which is why the long-run trajectory of human history keeps bending toward larger, more entangled, and less separable systems rather than back toward isolated ones.

Harari names three orders that first made it possible to imagine the whole world as one unit: the monetary order of merchants, the imperial order of conquerors, and the universal religions of prophets. Each could, in principle, include every human being, and the next three chapters follow each of them in turn.