Diversionary History
If there’s one thing everybody seems to agree about the history of zero, it’s that it was driven primarily by notational considerations. More specifically, zero was required to enable positional notation. The historical record reinforces this assumption, to such an extent that it becomes apparently obvious, and thus unproblematic.
For instance (grabbing what’s immediately to hand), John D Barrow’s The Book of Nothing organizes its discussion of ‘the Origin of Zero’ by relating how
… the zero sign and a positional significance when reading the value of a symbol, are features that lie at the heart of the development of efficient human counting systems.
Robert Kaplan, when discussing the retardation of Greek arithmetical notation, explains:
… the continuing lack of positional notation meant that [the Greeks] still had no symbol for zero.