  Based on a general variational principle, Noether's theorem is revisited. It
is shown that the so called pseudotensor problem of the gravitational
energy-momentum is a result of mis-reading Noether's theorem, and in fact, all
the Noether's conserved quantities are scalars. It is also shown, by using a
counter-example, that the non-localizability of gravitational energy-momentum
can not be attributed to the equivalence principle. As a direct consequence of
variational principle, a generalized Hamilton-Jacobi equation for the
Hamilton's principal functional is obtained.
