  I present arguments based on dispersion theory and the existence of charged
BPS states of small charge, that maximally supersymmetric SUGRA is not a finite
theory. The essence of the argument is that the perturbative construction of
the theory implies that scattering amplitudes are invariant under a continuous
SU(8) global symmetry, which is broken by contributions from virtual BPS
states. Conventional estimates of the contributions of those states above
production threshold, shows that they should be order one. If the amplitude
satisfies a dispersion relation with a finite number of subtractions, as has
recently been argued by Giddings and Porto [1], then SU(8) violating amplitudes
appear at finite orders in the low energy expansion. We also make a brief
remark about the inconsistency of the idea of classicalization in
non-gravitational theories.
