Here are some sentences from Fred Dretske's book Naturalising the Mind:
For a materialist there are no facts that are accessible to only one person … If the subjective life of another being, what it is like to be that creature, seems inaccessible, this must be because we fail to understand what we are talking about when we talk about its subjective states. If S feels some way, and its feeling some way is a material state, how can it be impossible for us to know how S feels? Though each of us has direct information about our own experiences, there is no privileged access. If you know where to look, you can get the same information I have about the character of my experiences. This is a result of thinking about the mind in naturalistic terms. Subjectivity becomes part of the objective order. For materialists, this is as it should be.