Haskell Curry made this argument in his "Outlines of a Formalist Philosophy of Mathematics": http://www.amazon.com/Outlines-Formalist-Philosophy-Mathematics-Stu

Haskell Curry made this argument in his "Outlines of a Formalist Philosophy of Mathematics": http://www.amazon.com/Outlines-Formalist-Philosophy-Mathematics-Study/dp/072042206X http://www.amazon.com/Outlines-Formalist-Philosophy-Mathemat... His idea is that mathematics is the empirical study of the implications of systems of rules.