I am interested in the exploring the possible answers to this post’s titular question available to those who answer “yes” to the following questions. Do you have qualia? Can others have qualia?
At first glance, it seems that there would be two general options in answering “How do you know what you are talking about when you talk about qualia?”;
option 1: by description.
option 2: by inner ostension.
One “problem” with option 1 is that it opens the door to the identification of qualia with physical and/or functional kinds. This, of course, is not really a problem unless you were hoping you would get to be a dualist at the end of the day.
Option 2 leads to similar “problems”. The first is that if your physical or functional doppleganger has states that it knows by inner ostension, then what is there to prevent the identification of such physical/functional states with qualia? If the answer is that you can imagine your dopplganger having those phys/func states w/o having qualia, then there’s a serious question of whether you do indeed know what you are talking about when you answer yes to the question of whether others can have qualia. This leads to the (Wittgensteinian?) question of how you can coherently conceive of this sort of thing, a thing you know by inner ostension as an element of your awareness, as existing independently of your awareness. How is it that inner ostension gives you the grasp of something that may also exist outside of your mental act of ostension? The trick will involve answering this latter question in a way that isn’t simply a tacit switch from option 2 to option 1.
Figs. 1 & 2: Neon Color Spreading. Are the gaps beetween the black and the blue being filled in by your brain with qualia? If you answer that question, how do you know that you know what you are talking about?