  We show that the rapid formation of super-massive black holes in quasars can
indeed be understood in terms of major galaxy mergers followed by disk
accretion. The necessary short disk evolution time can be achieved provided the
disk viscosity is sufficiently large, which, for instance, is the case for
hydrodynamic turbulence, unlimited by shock dissipation. We present numerical
calculations for a representative case. This general picture can account for
(a) the presence of highly luminous quasars at redshifts z > 6; (b) for the
peak in quasar activity at z ~ 2; and (c) for a subsequent rapid disappearance
of quasars at later epochs.
