  In these notes we prepare the ground for a systematic investigation into the
issues of black hole fluctuations and backreaction by discussing the
formulation of the problem, commenting on possible advantages and shortcomings
of existing works, and introducing our own approach via a stochastic
semiclassical theory of gravity based on the Einstein-Langevin equation and the
fluctuation-dissipation relation for a self-consistent description of metric
fluctuations and dissipative dynamics of the black hole with backreaction of
its Hawking radiance.
