We Know Their Drains, Not Their Minds
Five million people, a million square kilometres, sanitation Europe would not match for four thousand years, and not one readable word. Our ranking of ancient civilisations is substantially a ranking by preservation.
A child in Mohenjo-daro around 2500 BCE is growing up with better sanitation than most Europeans would have until the nineteenth century.
Her street is laid out on a grid. Her house has a bathing platform and a private drain, which feeds into a covered municipal sewer running under the road, with inspection points at intervals so it can be cleared. The bricks in her wall are the same dimensions as bricks in cities hundreds of kilometres away. So are the weights her father uses in the market, calibrated to the same ratios across a territory of a million square kilometres.
The Indus Valley civilisation was contemporary with Egypt and Mesopotamia and by some measures larger than both: at least five major cities, hundreds of smaller settlements, perhaps five million people.
And we cannot read a single word they wrote.
The script exists. Thousands of seal stones, tablets and potsherds carry it, and over four hundred distinct signs have been catalogued. It has never been deciphered and may never be. The inscriptions are desperately short, five signs on average. There is no bilingual text to serve as a Rosetta Stone. The underlying language is unknown, and the candidates are politically loaded in ways that have not helped. Linguists, cryptographers and pattern-recognition systems have all had a go. No consensus.