  We argue here why CP violating phase Phi in the quark mixing matrix is
maximal, that is, Phi=90 degrees. In the Standard Model CP violation is related
to the Jarlskog invariant J, which can be obtained from non commuting Hermitian
mass matrices. In this article we derive the conditions to have Hermitian mass
matrices which give maximal Jarlskog invariant J and maximal CP violating phase
Phi. We find that all squared moduli of the quark mixing elements have a
singular point when the CP violation phase Phi takes the value Phi=90 degrees.
This special feature of the Jarlskog invariant J and the quark mixing matrix is
a clear and precise indication that CP violating Phase Phi is maximal in order
to let nature treat democratically all of the quark mixing matrix moduli.
