Comment by EllisD on Rationality Quotes March 2012 · 2012-03-02T14:24:29.107Z · LW · GW

Whether a mathematical proposition is true or not is indeed independent of physics. But the proof of such a proposition is a matter of physics only. There is no such thing as abstractly proving something, just as there is no such thing as abstractly knowing something. Mathematical truth is absolutely necessary and transcendent, but all knowledge is generated by physical processes, and its scope and limitations are conditioned by the laws of nature.

-David Deutsch, The Beginning of Infinity.