Counting and recording quantity

c. 20,000 years ago Number and measure method

The oldest finds read as counting are bones with rows of notches: the Lebombo bone (44-42 thousand years old) and the Ishango bone (about 20 thousand years old). What exactly they record is still disputed. De Heinzelin, who found the Ishango bone, saw arithmetic in the groups of notches; Marshack read them as a lunar calendar; Pletser and Huylebrouck as base-12 counting. Keller (2010) called all these readings "mathematical fiction": once you decide that the notches stand for numbers, the bone will confirm any hypothesis. Only one thing is beyond doubt: the notches were made deliberately.

Why the map starts here. If the notches really are counting, here a quantity exists apart from the things themselves: not "so many animals" but marks that can be compared and added to without holding the number in your head.

Why this date

archaeological evidence, interpretation disputed. Ishango bone: about 20,000 years old (Brooks and Smith 1987; Keller 2010: "20.000 ans avant nos jours"). Lebombo bone from Border Cave: 44-42 ka (d'Errico et al. 2012), but its reading as a tally stick remains a conjecture. The axis position follows Ishango as the best-studied object

What grew out of it

Node sources

"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.

Further reading

Not evidence: these carry no quotation and support nothing we wrote. They are books and scans to read next.

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