I enjoyed Lakoff and Núñez's section on this in their book Where Mathematics Comes From[1]. The relevent pages are available at Google Books[2]. 1- http://en.

I enjoyed Lakoff and Núñez's section on this in their book Where Mathematics Comes From[1]. The relevent pages are available at Google Books[2]. 1- http://en.wikipedia.org/wiki/Where_Mathematics_Comes_From http://en.wikipedia.org/wiki/Where_Mathematics_Comes_From 2- http://books.google.com/books?id=YXv6SEjTNKsC&pg=PA432&lpg=432 http://books.google.com/books?id=YXv6SEjTNKsC&pg=PA432&#...