Through the looking glass : mere mirage or a road not taken?

Maximal parity violation in weak interactions was a radical discovery
in its time.  Is it now an orthodoxy to be upturned or still a guiding
principle for unification of fundamental interactions? With the
discovery of neutrino masses the possibility is strong that the world
could be parity symmetric in some sense, with the observed asymmetry a
consequence of spontaneous symmetry breaking. After an overview of
these issues including the see-saw mechanism for neutrino masses, I
show that any model that naturally accommodates parity symmetry also
has important implications for cosmology. New symmetries entail
topological objects upon symmetry breakdown and their presence can
play a variety of roles in cosmic evolution. Taking account of these
can be very suggestive as well as restrictive and can be a guide to
model building in Particle Physics. I will review some examples from
left-right symmetric models.