  The membrane paradigm is the remarkable view that, to an external observer, a
black hole appears to behave exactly like a dynamical fluid membrane, obeying
such pre-relativistic equations as Ohm's law and the Navier-Stokes equation. It
has traditionally been derived by manipulating the equations of motion. Here we
provide an action formulation of this picture, clarifying what underlies the
paradigm, and simplifying the derivations. Within this framework, we derive
previous membrane results, and extend them to dyonic black hole solutions. We
discuss how it is that an action can produce dissipative equations. Using a
Euclidean path integral, we show that familiar semi-classical thermodynamic
properties of black holes also emerge from the membrane action. Finally, in a
Hamiltonian description, we establish the validity of a minimum entropy
production principle for black holes.
