  We show that Dirac neutrino masses of the right size can arise from the
Kahler potential of supergravity. They are proportional to the supersymmetry
and the electroweak breaking scales. We find that they have the experimentally
observed value provided that the ultraviolet cut-off of the Minimal
Supersymmetric Standard Model (MSSM) is between the Grand Unification (GUT)
scale and the heterotic string scale. If lepton number is not conserved, then
relatively suppressed Majorana masses can also be present, resulting in
pseudo-Dirac neutrino masses.
