  I describe the treatment of gravity as a quantum effective field theory. This
allows a natural separation of the (known) low energy quantum effects from the
(unknown) high energy contributions. Within this framework, gravity is a well
behaved quantum field theory at ordinary energies. In studying the class of
quantum corrections at low energy, the dominant effects at large distance can
be isolated, as these are due to the propagation of the massless particles
(including gravitons) of the theory and are manifested in the
nonlocal/nonanalytic contributions to vertex functions and propagators. These
leading quantum corrections are parameter-free and represent necessary
consequences of quantum gravity. The methodology is illustrated by a
calculation of the leading quantum corrections to the gravitational interaction
of two heavy masses.
