That is what is at stake here. That's why I made the very important distinction between measuring and seeing. My argument is that a machine can measure, but it can't measure in one of the ways that you and I measure. It can't measure by seeing, that is, by having a visual impression. Machines can't have visual impressions.
Minds have visual impressions.
That is a characteristic of consciousness, not of machinery. I didn't say the word blue as was used in the letter. A word is a physical symbol that stands for something else that is not physical. That non-physical thing is the word's meaning. The computer can't use words like that.