  Our method of analysis, which led to existence of sigma and kappa mesons, is
reviewed and examined from a viewpoint of general S-matrix. It is shown that
the method is consistent with the constraints from chiral symmetry and
unitarity. Accordingly the long-believed common analyses of pipi (Kpi)
scattering and production processes, based on elastic unitarity, prove to lose
its theoretical base. The observed phase motion by 180 degrees of sigma shows
also the validity of our method.
