  Euclidean quantum gravity (EQG) separates into a local theory and a global
theory. The local theory operates in every compact $d$-manifold with boundary
to produce a state on the boundary. The global theory then sums these boundary
states over the diffeomorphism classes of $d$-manifolds with boundary to make
the Hartle-Hawking state. Global EQG is formulated here as classical
statistical physics. The Hartle-Hawking state is the probability measure of a
mathematically natural classical statistical system, analogous to the
functional measure of euclidean quantum field theory. General principles of
global EQG determine the numerical weights $w(M)$ in the sum over
diffeomorphism classes $M$.
