  In this paper delivered by Murray Gell-Mann at the Stony Brook Supergravity
Workshop in 1979, several paths to unification are discussed, from N=8
supergravity to $SU_5$, $SO_{10}$, and $E_6$. Generalizations of $SO_{10}$ to
spinor representations of larger groups are introduced. A natural mechanism for
generating tiny neutrino masses is proposed in the context of $SO_{10}$, and
finally, focus on $SU_3$ rather than $SU_2$ or $SO_3$ family symmetries is
noted.
