  The role of space-time torsion in general relativity is reviewed in
accordance with some recent results on the subject. It is shown that, according
to the connection compatibility condition, the usual Riemannian volume element
is not appropriate in the presence of torsion. A new volume element is proposed
and used in the Lagrangian formulation for Einstein-Cartan theory of gravity.
  The dynamical equations for the space-time geometry and for matter fields are
obtained, and some of their new predictions and features are discussed. In
particular, one has that torsion propagates and that gauge fields can interact
with torsion without the breaking of gauge invariance. It is shown also that
the new Einstein-Hilbert action for Einstein-Cartan theory may provide a
physical interpretation for dilaton gravity in terms of the non-riemannian
structure of space-time.
