TITLE: Is 1 + 1 = 2 a fact?
QUESTION [8 upvotes]: One of my colleagues tried to explain me that basic arithmetic is derived from nature. And hence its a fact. Another colleague tried to argue that humans came up with basic arithmetic and then tried to correlate with nature. 
All I want to know is when someone says 1 + 1 = 2, is it a fact?
If our whole civilization is started from scratch, would we still come up with same rules of mathematics?

REPLY [2 votes]: One could dispute your colleague's claims. For example, adding two drops of water together still gives you drop of water, which is also observed in nature. The question is quite philosophical and cannot be answered without more information, you could say that it depends on exactly what you mean... You may find the following article on counting from Rafael Núñez interesting: http://www.cogsci.ucsd.edu/~nunez/web/biot.pdf.