Comment by smcameron

I expected this to be about qualia. It's not. What I percieve to be red might be what you perceive to be blue, but we have no way to know this, because we will both call it by the same name. We have almost no insight into the qualia of others. Colorblindness is a chink in this armor. Not that I consider this a novel insight, it's something I thought of while a 10th grader back in 1984, and subsequently read about in books predating my own thoughts, such as Douglas Hofstadter's Metamagical Themas or Godel, Escher, Bach, or some other book I can't recall, though it seems quite obvious in any case.