  We describe how one may use either the superPoincar\'e algebra or the
exceptional algebra to construct maximal supergravity theories in the
light-cone formalism. The d=4 construction shows both symmetries albeit in a
non-linearly realized manner. In d=11, we find that we have to choose which of
these two symmetries to use, in constructing the theory. In order to understand
the other "unused" symmetry, one has to perform a highly non-trivial field
redefinition. We argue that this shows that one cannot trust counterterm
arguments that do not take the full symmetry of the theory into account.
Finally we discuss possible consequences for Superstring theory and M-theory.
