>The problem is that there could conceivably be brains that perform all the same sensory and decision-making functions as ours but in which there is no conscious experience. That is, there could be brains that react as though sad but that don’t feel sadness, brains that can discriminate between wavelengths of light but that don’t see red or yellow or blue
That's an assertion I believe to not be so obvious it can be assumed to be correct with no argument to the contrary. If you can't define consciousness why do you believe it exists independent of these other systems and that these other systems exist independent of it? The study of consciousness is absolutely full of non-falsifiable claims like this. We decide apes and dogs and frogs and ants are not sapient but that is an outside observation. It may be as erroneous as looking at Specimen A and its great to the five hundredth generation ancestor and deciding that because they should count as two separate species there must have been some momentous leap in the middle to make Specimen A possible. Consciousness could easily be a smooth spectrum from human to insect and we wouldn't know it because everything next to our level is extinct.
That's an assertion I believe to not be so obvious it can be assumed to be correct with no argument to the contrary. If you can't define consciousness why do you believe it exists independent of these other systems and that these other systems exist independent of it? The study of consciousness is absolutely full of non-falsifiable claims like this. We decide apes and dogs and frogs and ants are not sapient but that is an outside observation. It may be as erroneous as looking at Specimen A and its great to the five hundredth generation ancestor and deciding that because they should count as two separate species there must have been some momentous leap in the middle to make Specimen A possible. Consciousness could easily be a smooth spectrum from human to insect and we wouldn't know it because everything next to our level is extinct.