Is indirect realism self undermining? Couldn't there be a metaphysics of perception? — Moliere
I suppose that depends on whether or not you're a dualist. If there is such a thing as a non-physical mind then it is literally
meta physics.
Isn't that the distinction between direct and indirect? — Moliere
I think the distinction is that the direct realist believes that apples and their properties are manifest in conscious experience such that how an object appears is how it is (even when it doesn't appear), whereas the indirect realist believes that the properties which are manifest in conscious experience (e.g. shapes and colours and tastes and smells) are properties only of conscious experience, albeit causally covariant with (and perhaps in a sense
representative of) apples and their properties.
Such as RussellA's worlds, where there is an external world and an internal world? — Moliere
I wouldn't read too much into such terminology. After all, there's no metaphysics involved when we talk about the "world of show business".
And the indirect access adds a metaphysical entity in between ourselves and reality, which is directly perceived but not real. — Moliere
There's nothing metaphysical about it (unless the mind is non-physical). Just look at perception from a purely biological perspective. Electromagnetic radiation stimulates the rods and cones in the eyes. This sends signals to the occipital lobe which processes visual information, which is then sent to the temporal lobe where the visual information is processed into memory and to the frontal lobe where the visual information is processed into intellectual reasoning and decision-making.
Now what happens if we ignore the eyes entirely and find some other means to activate the occipital lobe, such as with
cortical implants or the ordinary case of dreaming? I would say that the subject undergoes a conscious experience. And I would say that their conscious experience is one of visual imagery, such as shapes and colours. Seeing shapes and colours does not require electromagnetic radiation stimulating the rods and cones in the eyes (or an apple to reflect said light). Seeing shapes and colours only requires the activation of the appropriate parts of the cerebral cortex.
Given that seeing shapes and colours only requires the activation of the appropriate parts of the cerebral cortex, regardless of what triggers it, it's understandable why one would argue that the shapes and colours we see are "in the head" and not properties of apples. Seeing shapes and colours is no different in principle to feeling pain or hot or cold.
The brain activates, a sensation occurs, and we are cognitively aware of this sensation. We then (often) infer from this sensation the existence of some responsible external stimulus. The mistaken naive view is to think that the quality of this sensation (e.g. shape or colour or smell or taste) is a property of the external stimulus.