  Earlier work suggested that the in-medium $\pi N$ threshold isovector
amplitude $b_1(\rho)$ gets renormalized in pionic atoms by about 30% away from
its $\rho=0$ free-space value, relating such renormalization to the leading
low-density decrease of the in-medium quark condensate $<\bar q q>$ and the
pion decay constant $f_{\pi}$ in terms of the pion-nucleon $\sigma$ term
$\sigma_{\pi N}$. Accepting the validity of this approach, we extracted
$\sigma_{\pi N}$ from a large-scale fit of pionic-atom level shift and width
data across the periodic table. Our fitted value $\sigma_{\pi N}=57\pm 7$ MeV
is robust with respect to variation of $\pi N$ interaction terms other than the
isovector $s$-wave term with which $\sigma_{\pi N}$ was associated. Higher
order corrections to the leading order in density involve some cancellations,
suggesting thereby only a few percent overall systematic uncertainty. The value
of $\sigma_{\pi N}$ derived here agrees with values obtained in several recent
studies based on near-threshold $\pi N$ phenomenology, but sharply disagrees
with values obtained in recent direct lattice QCD calculations.
