Comment on "On the Origin of the OZI Rule in QCD", by N. Isgur and H. B. Thacker

We comment on the recent paper (hep-lat/0005006) by Isgur and Thacker on the origin of the OZI rule in QCD. We show that instantons explain the sign and magnitude of the observed OZI-violating amplitude in all mesonic channels, not just in the $\eta'$ channel. We comment on the role of instantons in hadronic spectroscopy and the relation between instantons and the large $N_c$ limit of QCD.