  The $\pi N$ system in decays of $J/\psi\to\bar NN\pi$ is limited to be
isospin 1/2 by isospin conservation. This provides a big advantage in studying
$N^*\to \pi N$ compared with $\pi N$ and $\gamma N$ experiments which mix
isospin 1/2 and 3/2 for the $\pi N$ system. Using 58 million $J/\psi$ decays
collected with the Beijing Electron Positron Collider, more than 100 thousand
$J/\psi \to p \pi^- \bar n + c.c.$ events are obtained. Besides two well known
$N^*$ peaks at 1500 MeV and 1670 MeV, there are two new, clear $N^*$ peaks in
the $p\pi$ invariant mass spectrum around 1360 MeV and 2030 MeV. They are the
first direct observation of the $N^*(1440)$ peak and a long-sought "missing"
$N^*$ peak above 2 GeV in the $\pi N$ invariant mass spectrum. A simple
Breit-Wigner fit gives the mass and width for the $N^*(1440)$ peak as $1358\pm
6 \pm 16$ MeV and $179\pm 26\pm 50$ MeV, and for the new $N^*$ peak above 2 GeV
as $2068\pm 3^{+15}_{-40}$ MeV and $165\pm 14\pm 40$ MeV, respectively.
