  In-medium chiral perturbation theory is used to calculate the density
dependence of the quark condensate $<\bar qq>$. The corrections beyond the
linear density approximation are obtained by differentiating the interaction
contributions to the energy per particle of isospin-symmetric nuclear matter
with respect to the pion mass. Our calculation treats systematically the
effects from one-pion exchange (with $m_\pi$-dependent vertex corrections),
iterated $1\pi$-exchange, and irreducible $2\pi$-exchange including
intermediate $\Delta(1232)$-isobar excitations, with Pauli-blocking corrections
up to three-loop order. We find a strong and non-linear dependence of the
``dropping'' in-medium condensate on the actual value of the pion (or light
quark) mass. In the chiral limit, $m_\pi=0$, chiral restoration appears to be
reached already at about 1.5 times normal nuclear matter density. By contrast,
for the physical pion mass, $m_\pi = 135 $MeV, the in-medium condensate
stabilizes at about 60% of its vacuum value above that same density. Effects
from $2\pi$-exchange with virtual $\Delta(1232)$-isobar excitations turn out to
be crucial in generating such pronounced deviations from the linear density
approximation above $\rho_0$. The hindered tendency towards chiral symmetry
restoration provides a justification for using pions and nucleons as effective
low-energy degrees of freedom at least up to twice nuclear matter density.
