  Now consider a counterfactual spectrum inversion scenario in which “spectrum inversion is rife”. Invert has been spectrally inverted with respect to some other members of his community since birth, all of whom use color terminology in much the same way. Nonvert is spectrally inverted with respect to his neighbor Invert, but—comparing  this scenario with the actual scenario described in the previous paragraph—is not spectrally inverted with respect to Humbert. Further suppose that Nonvert and his neighbor Invert use qualia terminology as introduced in section 1 above. Assume as a suppressed premise that this scenario is possible.