I understand that the belief in qualia may be based on a sensual illusion, but I can't get my head around illusionism. Obviously, illusionists deny that we experience any illusion, we just believe (or not) that we do.
But I am absolutely certain that, supposing qualia do not exist, I am experiencing (through touch, hearing etc.) the illusion of qualia. Isn't it up to them to account not for the belief or statement of belief but what it expresses? That's vacuously impossible, if the belief is true.
According to illusionists (Dennett 2019, 2020; Frankish 2016; Kammerer 2021), conscious experience is an illusion. It certainly seems to us that conscious experiences, and thus qualia (at least in sense (1) of the four senses distinguished at the beginning of this entry) exist, but in reality there are no such things. Qualia are like Santa Claus and the Easter Bunny (Dennett 2020). It is not being denied here that through the use of our senses, we genuinely encounter a wide range of qualities, for example, in perception, colors, auditory qualities such as pitch and loudness, various textures and aromas. But the qualities so encountered are not properties of experiences; for we do not genuinely undergo any experiences. To be sure, when we introspect, it certainly seems to us that we are the subjects of experiences with widely varying phenomenal character. But we are wrong... This position is not easy to take seriously; for what could be more obvious than the existence of conscious experience? Adherents of the view may respond that introspection simply leads us astray. On the basis of introspection, we believe that we undergo experiences (states with qualia in sense (1)), but the beliefs so formed are false. What would help strong illusionism here is a theory of introspection which can explain the apparent absurdity of the view.
What sort of argument would suffice to shift the burden of proof onto someone who claims they have experiences?