  In this paper the entropy of an eternal Schwarzschild black hole is studied
in the limit of infinite black hole mass. The problem is addressed from the
point of view of both canonical quantum gravity and superstring theory. The
entropy per unit area of a free scalar field propagating in a fixed black hole
background is shown to be quadratically divergent near the horizon. It is shown
that such quantum corrections to the entropy per unit area are equivalent to
the quantum corrections to the gravitational coupling. Unlike field theory,
superstring theory provides a set of identifiable configurations which give
rise to the classical contribution to the entropy per unit area. These
configurations can be understood as open superstrings with both ends attached
to the horizon. The entropy per unit area is shown to be finite to all orders
in superstring perturbation theory. The importance of these conclusions to the
resolution of the problem of black hole information loss is reiterated.
