  The cure to the $\ell=1$ Landau-Pomeranchuk (L-P) instabilities in
translationally invariant fermions is shown to be a state with an anisotropic
gap at the fermi-surface. For higher $\ell$ and for fermions on a lattice,
general criteria for long wavelength instabilities and their cure are found in
terms of the derivatives of the single particle self-energy with respect to
momentum for spin-symmetric instabilities and with respect to magnetic field
for spin-antisymmetric instabilities. The results may be relevant to
identifying hidden order parameters found in many metals.
