There are many propositions that cannot be doubted, so that's insufficiently precise. For instance, I do not doubt that I perceive things via my senses, but perception doesn't require consciousness.
It also leaves entirely undefined what "doubt" means. Your attempted definition would seem to assume that only conscious entities can "doubt", but is that really true?
"Accordingly, seeing that our senses sometimes deceive us, I was willing to suppose that there existed nothing really such as they presented to us; and because some men err in reasoning, and fall into paralogisms, even on the simplest matters of geometry, I, convinced that I was as open to error as any other, rejected as false all the reasonings I had hitherto taken for demonstrations; and finally, when I considered that the very same thoughts (presentations) which we experience when awake may also be experienced when we are asleep, while there is at that time not one of them true, I supposed that all the objects (presentations) that had ever entered into my mind when awake, had in them no more truth than the illusions of my dreams.
But immediately upon this I observed that, whilst I thus wished to think that all was false, it was absolutely necessary that I, who thus thought, should be somewhat; and as I observed that this truth, I think, therefore I am (COGITO ERGO SUM), was so certain and of such evidence that no ground of doubt, however extravagant, could be alleged by the sceptics capable of shaking it, I concluded that I might, without scruple, accept it as the first principle of the philosophy of which I was in search."
Begs the question: it assume the existence of "I" (a subject) in proving the existence of "I". The fallacy-free version is, "this is a thought, therefore thoughts exist".
> There are many propositions that cannot be doubted, so that's insufficiently precise.
I can even doubt that 1 + 1 = 2, because I cannot prove to myself that I am not completely crazy. This is not a new idea at all, it's the "cogito ergo sum" of Descartes.
> Your attempted definition would seem to assume that only conscious entities can "doubt", but is that really true?
It is not necessary to assume that. It is enough to assume that a conscious entity cannot doubt its own consciousness in good faith.
> I can even doubt that 1 + 1 = 2, because I cannot prove to myself that I am not completely crazy.
Even if completely crazy, you still doubtless perceive and experience.
> It is enough to assume that a conscious entity cannot doubt its own consciousness in good faith.
If by "consciousness" you mean subjectivity, then I disagree. We cannot doubt that we have something that we conclude is subjectivity. The real question/the hard problem is determining whether such a conclusion is true.
The act of perception directly implies that some self-aware entity is perceiving. For instance the camera is capturing the image, but you can't say "this camera is perceiving" We rather say "this camera is taking picture"
> I do not doubt that I perceive things via my senses
You could if you were stuck in Inception land. We dream that we perceive things. Also if you were a brain in a vat, you would not be perceiving anything.
I actually didn't mean to say "via my senses", what I meant is that I definitely perceive things, period. That encompasses both of your scenarios. Thanks for the correction!
It's more correct to say you have experiences of perception. But those experiences are not always true (the tree you dream of seeing is imaginary), and thus it's possible to doubt them, and also create skeptical scenarios where you never truly perceive anything.
Arguably, Neo never actually perceived anything until he took the red pill and woke up.
> Arguably, Neo never actually perceived anything until he took the red pill and woke up.
I don't think that's possible. His perceptual faculties would have been completely undeveloped in that case, so he wouldn't have even been able to see, stand, hear, or anything. Arguably, the matrix made use of his perceptual faculties. It would be orders of magnitude easier to do so than trying to reproduce them in the vat apparatus.
I think people are fond of trying to separate perception and experience, but I'm not sure that's valid. I don't think an eliminativist would make this distinction, for example.
> I think people are fond of trying to separate perception and experience, but I'm not sure that's valid. I don't think an eliminativist would make this distinction, for example.
Problem for the eliminativist is that there are experiences which aren't perceptual. The reason for thinking we can separate perceptual experience from perceiving is because it is brain activation which results in an experience, which can happen without sensory stimulation. When we dream, we're activating our visual and auditory cortexes to create those experiences. Electrodes or magnetic stimulation can do the same on a much cruder level. And a schizophrenic may hear voices because their brain fails to distinguish between internal thoughts and external voices.
> When we dream, we're activating our visual and auditory cortexes to create those experiences.
Right, and because there's little difference I generally refer to them all as perceptual. It seems perfectly cogent to say "electrode stimulation can create visual perceptions". I think "experience" in most such sentences is simply redundant. It either refers specifically to the activation of perceptual faculties, or it refers to something "beyond" perceptual faculties which may not exist (qualia).
There are many propositions that cannot be doubted, so that's insufficiently precise. For instance, I do not doubt that I perceive things via my senses, but perception doesn't require consciousness.
It also leaves entirely undefined what "doubt" means. Your attempted definition would seem to assume that only conscious entities can "doubt", but is that really true?