I must admit that I rather gave up after a while. Then I got absorbed in my real life and lost interest. Now I find myself with all these fascinating comments.

Since coming back to philosophy, I've become very taken with the idea of enactive psychology. The fact that we are active in the world seems to me fundamental to understanding what is going on in our heads. The idea that we are primarily heads and that our bodies are an accidental appendage is a natural focus for philosophy insofar as it is a theoretical discipline, but also a big mistake. I haven't readd enough to count myself an expert, so for the time being this is just a useful idea.

What I fail to grasp about Popper is why he deploys his concept of different worlds. Understanding the differences between his worlds is important, but one needs a concept that allows for their interconnection. I find the concept of a category quite sufficient for doing this, even though the connection between categories is pretty mysterious as well. Nonetheless, insisting that maths, information, experiences, mass and energy are all in the same world keeps the focus right.

There is somewhat of a gap in the thinking about the private language argument. It is perfectly true that my relationship to my own experience is different from my relationship to your experience. Normally, this is expressed by saying that I own my own experiences and you own yours. This captures part of the story. No-one else can own my car or house - until I cease to own it. The problem is that experiences are not transferable in that way.

It would be better to point out that no-one else can live my life, or eat my meal or have my cold. But that still doesn't capture the difference.

There is a feeling that language cannot capture my experience. Description is not adequate, but language has other resources. Poetry captures experience in a way that description does not. Metaphor is also very powerful - remember Locke's famous example - red is the sound of trumpets. That conjures up synaesthesia, which is a real phenomenon - and not a private one, even though I cannot experience it.

Only philosophers could be so hypnotized as to fail to notice that describing an experience is not having it. There's nothing puzzling about it. Walking down a street is different from being pushed in a wheel chair. Both modes achieve something of the same end, but in different ways. There's nothing wrong with either of them - they just do different jobs. Similarly with describing a bungee jump and jumping it.

Oh, sorry, I should have said, after my remark about poetry, that language does not only describe, it also expresses and that is an important function when it comes to our experiences. But it is more like poetry than prose.

If I understood what telepathy is supposed to be, I might be able to express an opinion on what you say about it. I prefer to stick with what I know, without ignoring the fact that there is much that I do not know. If we could live for a thousand years, amazing and unthought things may occur; but also things that we imagine will turn out to be impossible. No point in going there.

On Popper, if one posits more that one world, or substance, the question will always arise, if two, why not three, or four or... It those worlds are in communication, why not stick with one and a pluralist concept of categories. Then one can classify the world as one finds it.

By the way, can you clarify your reference in one of your comments before this discussion began. You ask "Can you summarize the "argument" in 3.4 2nd Answer from PP "But this is just what is in question." on?" I find the quotation in PI 186, but you refer to "PP", so I think you must be quoting from something else. I used to know everything published, but that's no longer true.