More notes – from a different book: Philosophy of Mind: The Key Thinkers, edited by Andrew Bailey.
“The argument from transparency is based on introspective observations about what we do and do not notice in experience. In a nutshell, the introspective observations are these:
1. When we pay attention to our experiences, we don’t notice qualitative properties attributed to our experiences themselves.
2. When we pay attention to our experiences, the qualitative properties that we notice are attributed to the objects of our experiences.
To borrow Harman’s (1990) famous example, when Eloise sees a tree, she notices the greenness of the leaves, the brownness of the trunk and the overall shape of the tree. All the qualities that she notices seem to her to be properties of external objects, not of her experience. Our experiences seem to be characterized by properties of the sorts that external objects have, not properties that sense data or other mental entities have. Moreover, introspection reveals exactly the same properties whether or not corresponding objects exist. All this suggests that the nature of experience is exhausted by represented properties of represented objects.
Though advocates of transparency focus on visual experiences, the transparency observation is supposed to hold for all experiences. When we introspect on our auditory experiences, for example, we notice properties of sounds, such as their loudness and pitch, but we don’t notiec any qualitative features of our auditory experience themselves.
The claim that experience is transparent has been challenged on various grounds. …”