A friend asked me how Berkeley can be refuted. I am fond of ethical insights as epistemically primary. Here is an ethical insight: I have a special authority over my body. But on Berkeley’s view, my body is co-constituted by my ideas and everybody else’s ideas. My ideas are a part of me, yours are a part of you, and so my body is partly constituted by my parts and partly by your parts, Now it is difficult to see why I have special authority over it.
One might say that I have more in the way of perceptions of my body than you do, because I have kinesthetic sensation, introspection, etc. While that is typically true, it is only typically true. If you are doing neurosurgery on me, and I am unconscious, then my body is not constituted at all by my ideas at the time, and you have a lot of perceptions of my body that I never do.
