"Math, like diamonds, truly seems to be forever. If one 'goes Platonic' with math, one has to face... philosophical consequences... the notion of goes out the window. Physicalism is the position that the only things that exist are those that have physical extension... and last time I checked, the idea of circle, or Fermat’s theorem, did not have physical extension. It is true that physicalism is now a sophisticated doctrine that includes not just material objects and energy, but also, for instance, physical forces and information. But it isn’t immediately obvious to me that mathematical objects neatly fall into even an extended physicalist ontology."