  However, Argument E is not obviously sound. The premise in need of most defense is  P3.[46]  When qualia terminology was introduced in section 1, it was tacitly presupposed that spectrum inversion was not rife. In Invert’s and Nonvert’s community, that presupposition is false, and so it should not be surprising if the attempt to introduce ‘\(Q_{R}\)’ into their public language fails. But in Humbert’s community the presupposition is true; so why wouldn’t ‘\(Q_{R}\)’, as the members of this community use it, successfully refer to the quale distinctive of Humbert’s experiences of red  things?[47]