Definition
Big History is an academic and popular movement, most strongly associated with the historian David Christian, that tells the human story as one strand inside a much longer narrative: the Big Bang, the formation of stars and planets, the origin of life on Earth, the emergence of multicellular organisms, the rise of mammals, and only then the appearance of Homo sapiens. Harari's Sapiens is one of its best-known popularizations.
The defining move is scale. Where conventional history starts with writing and political states, Big History starts at 13.8 billion years ago and treats human civilization as a recent, contingent event in a long sequence.
Why it matters
How it works
A Big History narrative typically organizes time into thresholds — moments when a new kind of complexity becomes possible. Christian's canonical list is eight: Big Bang, stars, elements, planets, life, humans, agriculture, modernity. Harari simplifies to three revolutions: Cognitive, Agricultural, Scientific.
The genre is less a research method than a frame. Its value is the perspective shift it imposes: any claim about human nature has to survive contact with the biological and cosmological context that produced it.