We use a variational procedure to study finite density QCD in an
approximation in which the interaction between quarks is modelled by that
induced by instantons. We find that uniform states with conventional chiral
symmetry breaking have negative pressure with respect to empty space at all but
the lowest densities, and are therefore unstable. This is a precisely defined
phenomenon which motivates the basic picture of hadrons assumed in the MIT bag
model, with nucleons as droplets of chiral symmetry restored phase. This
suggests that the phase transition to a chirally symmetric phase occurs by
percolation of preexisting droplets of the symmetric phase, and in these
proceedings we expand upon our previous presentation of this observation. At
all densities high enough that the chirally symmetric phase fills space, color
symmetry is broken by the formation of a condensate of quark Cooper pairs.
A plausible ordering scheme leads to a substantial gap in a Lorentz scalar
channel involving quarks of two colors.Comment: 12 pages; latex with ptptex; Contribution to appear in the
proceedings of the YKIS 97 Worshop, Kyot