Full Idea
The pattern of the numeral series that is grasped by a child exists nowhere in nature outside human languages, so the human race cannot possibly have discerned this pattern by abstracting it from some natural context.
Gist of Idea
The numbers don't exist in nature, so they cannot have been abstracted from there into our languages
Source
Peter Geach (Mental Acts: their content and their objects [1957], §8)
Book Reference
Geach,Peter: 'Mental Acts: Their content and their objects' [RKP 1971], p.31
A Reaction
This is a spectacular non sequitur, which begs the question. Abstractionists precisely claim that the process of abstraction brings numerals into human language from the natural context. Structuralism is an attempt to explain the process.