  We present a study of the optical brightness profiles of early type galaxies,
using a number of samples of radio galaxies and optically selected elliptical
galaxies. For the radio galaxy samples--B2 of Fanaroff-Riley type I and 3C of
Fanaroff-Riley type II-- we determined a number of parameters that describe a
"Nuker-law" profile, which were compared with those already known for the
optically selected objects. We find that radio active galaxies are always of
the "core" type (i.e. an inner Nuker law slope gamma < 0.3). However, there are
core-type galaxies which harbor no significant radio source and which are
indistinguishable from the radio active galaxies. We do not find any radio
detected galaxy with a power law profile (gamma > 0.5). This difference is not
due to any effect with absolute magnitude, since in a region of overlap in
magnitude the dichotomy between radio active and radio quiescent galaxies
remains. We speculate that core-type objects represent the galaxies that have
been, are, or may become, radio active at some stage in their lives; active and
non-active core-type galaxies are therefore identical in all respects except
their eventual radio-activity: on HST scales we do not find any relationship
between boxiness and radio-activity. There is a fundamental plane, defined by
the parameters of the core (break radius r_b and break brightness mu_b), which
is seen in the strong correlation between r_b and mu_b. The break radius is
also linearly proportional to the optical Luminosity in the $I$ band. Moreover,
for the few galaxies with an independently measured black hole mass, the break
radius turns out to be tightly correlated with M_{BH}. The black hole mass
correlates even better with the combination of fundamental plane parameters r_b
and mu_b, which represents the central velocity dispersion.
