  We discuss the application of the permutation group S_N to a few problems in
hadron physics. A method is proposed for matching a quark model Hamiltonian
onto the effective Hamiltonian of the 1/Nc expansion, which makes use of the
transformation properties of the states and operators under S_N. This method is
used to obtain information about the spin-flavor structure of the quark
interaction Hamiltonian from the spectrum of the negative parity L=1 excited
baryons. Assuming the most general 2-body quark Hamiltonian, we derive two
correlations among the masses and mixing angles of these states which should
hold in any quark model. These correlations constrain the mixing angles, and
can be used to test for the presence of 3-body quark interactions. We find that
the pure gluon-exchange model is disfavored by data, independently of any
assumptions about the hadronic wave functions.
