the other way of thinking about it is that we don't know if we share a sense of "red", aside from merely being consistent with other compatible nodes (other hum

the other way of thinking about it is that we don't know if we share a sense of "red", aside from merely being consistent with other compatible nodes (other humans) in a network. the other node simply can distinguish "red" from "green" just like I can, but we don't know if they are perceiving that color the same way I am. whether it is a hardware difference in the rods, cones, other aspect of the eye, or computational aspect in the brain, we don't know. your supposition still relies on their being a separate entity to imagine, quantify or figure out, when that is not necessary. a tribunal of processes is enough for this "observer" phenomenon.