 a neuroscientist observing your brain being in that state. The neuroscientist’s observing of your brain state is itself a matter of the neuroscientist being in a distinct experiential state. Why think that the neuroscientist’s experience of your experience of a red tomato would resemble your experience of a red tomato or, more generally, that a neuroscientist’s observation of any conscious state would yield an awareness of ‘what it is like’ to be in that state? What is misleadingly described as your awareness of your own experiences is not your inward observation of those experiences, but simply having or undergoing those experiences. Assuming it makes sense to identify experiences with neurological states or processes, having and observing an experience are two very different things.
What of the elusive ‘what-it’s-like-ness’ of experiences? Knowing what it is like to experience red apparently requires having undergone a ‘red experience’, that is, having visually encountered something red. The point is a perfectly general epistemological point having nothing in particular to do with experiential qualities. Knowing what an echidna looks like requires having encountered an echidna, or a picture of an echidna, or a creature you know to be echidna-like.
None of this is especially controversial. If visually experiencing a tomato is a matter of being in a particular perceptual state, a scientist experiencing that state is a matter of the scientist being in a distinct perceptual state. These states – yours and the scientist’s – need not be similar, qualitatively or otherwise. And if knowing what it is like to be in a particular state is a matter of being – or having been – in that state, knowing what it is like to experience a tomato visually differs from knowing what it is like to experience a visual experience of a tomato. You could know either without knowing the other.
The subjectivity of experiences stems, not from their in-principle unobservability from the ‘outside’, but from the relatively humdrum distinction between something being in a particular state and someone observing that state. The distinction applies to mental and nonmental phenomena alike. A quantity of water being in a liquid state is one thing, you observing the water being in that state something else altogether.
Let’s not make the Hard Problem harder than it needs to be.