Abstract :
The divide between quantum theory and general relativity, more generally classical physics, has persisted. It is argued here that this is because the latter has, in the words of Witten, a Bosonic space-time underpinning, while the former has a Fermionic or non-commutative space-time underpinning: the purely quantum mechanical spin-half implies non-commutative space-time and vice versa.
