GS says consciousness the only thing in the world we can claim to know. “It is utterly unmysterious.” Referencing Bertrand Russell a century or so ago, he appears to be invoking Russell’s distinction between knowledge by acquaintance and knowledge by description. He is right, of course, in the sense that my immediate experience of anything is right there for me in the field of my awareness, effortlessly apprehended, requiring no reasoning or interpretation. I look across the street and see a blue object and instantly recognize it as a car, but even prior to the act of recognition I am immediately aware of (acquainted with) a blue patch in my visual field. I see it naked and exposed just as it is. That I am seeing a blue something or other is, as Strawson says, utterly unmysterious, completely present and clear. Similarly, if I am thinking of 5 + 3 = 8, I am immediately aware of thinking “5 + 3 = 8.” There is nothing mysterious about my direct experience of my own thinking. There it is, just 5+3 = 8, pure and simple, all by itself. I have no need of proof that I am thinking that thought, and no one can disprove it. The same is true for any other experience: feeling a pain in my toe or hearing a police siren, etc.. As GS says, I know these experiences immediately, because “having an experience is knowing the experience.”
Frankly, I find the phenomenon of ‘having an experience’ pretty mysterious. For example, who or what is this ’I’ that is having the experience? However, let’s go along with GS for a while, granting that immediate experience is unproblematic. But now he executes an astonishing right angle turn: as if by automatic transmission, he shifts the Hard Problem away from consciousness and parks it in the physics lab. By contrast with consciousness, he says, what is “deeply mysterious” is the “nature of physical stuff.” He cites Richard Feynman’s assertion that no one understands quantum theory. Hence, no one understands matter. Then GS quotes Russell for an exception: “The nature of physical stuff is mysterious “except insofar as consciousness is itself a form of physical stuff.” A “startling statement” indeed, but what exactly does it mean?