The gauge symmetries that underlie string theory arise from inner
automorphisms of the algebra of observables of the associated conformal field
theory. In this way it is possible to study broken and unbroken symmetries on
the same footing, and exhibit an infinite-dimensional supersymmetry algebra
that includes space-time diffeomorphisms and an infinite number of
spontaneously broken level-mixing symmetries. We review progress in this area,
culminating in the identification of a weighted tensor algebra as a subalgebra
of the full symmetry. We also briefly describe outstanding problems. Talk
presented at the Gursey memorial conference, Istanbul, Turkey, June, 1994.Comment: 5 pages, Plain TeX, no figure