Full Idea
The number 0 is not differentiated from 1 by its position in a progression, otherwise there would be no difference between starting with 0 and starting with 1. That is enough to show that numbers are not identifiable just as positions in structures.
Gist of Idea
Numbers aren't fixed by position in a structure; it won't tell you whether to start with 0 or 1
Source
Michael Dummett (Frege philosophy of mathematics [1991], Ch. 5)
Book Reference
Dummett,Michael: 'Frege: philosophy of mathematics' [Duckworth 1991], p.53
A Reaction
This sounds conclusive, but doesn't feel right. If numbers are a structure, then where you 'start' seems unimportant. Where do you 'start' in St Paul's Cathedral? Starting sounds like a constructivist concept for number theory.