I never saw anything contradictory with the idea that we might be subjects trapped in Matrix type scenario – a brains in vats scenario. Really, given the developments of things like computer generated virtual realities, in which we immerse ourself through gaming, it is easy to imagine the possibility of the simulations being so good that they are indistinguishable from our experiences in real life. And I can’t see anything contradictory with the idea that my body when I was a baby was hooked up to some virtual reality.
Now, there are arguments like Putnam’s one against brain in vats, which are related to certain theory of meaning of the words, but the possibility of virtual reality is so clear, seems to me, that denying the possibility that we are brains in vats on base of that argument, seems to me on par with denying that there is movement based on Zeno’s argument. Certainly there is value in Zeno’s paradoxes, but the value is not in proving that motion is impossible.
Anyway, not just that I don’t see anything contradictory in me being brain in a vat, which is placed within a virtual reality controlled by machines, but I don’t see anything contradictory with the idea that my brain was put in a vat, and that what it was and is getting from the inputs are signals generated by a random process, and that only by mere chance those inputs ended up such that I’m under the illusion that I’m a subject with a life I have, with wife, with kids, with all those experiences.
I think that even this turns out to be true, and every individual thing to which I was acquainted in my life turns out to have been an illusion, I will still have idea of wives, bachelors, chairs, books, philosophy, vats, brains, language, and so on… And, if by mere chance, it also turns out that these illusions were fully inline with what is there really in the world, my intended meanings in the virtual reality, will be fully inline with the meanings in this real world. I will be able to express my previous thoughts (the same thoughts I already had) about bachelors, about books, about brains, language, and so on…
What is interesting to me is how to relate my thinking that those kinds of scenario are possible with some of my externalist inclinations.
As I said, I believe that there is no such thing as ‘phenomenal experience’, and that ‘experience’ properly (and traditionally) refers to the events in the world in which we participate, and by which we are affected or from which we learn, OR (in alternative sense) it refers to the knowledge gained in that way.
Further, related to this, I don’t think there are concepts, if by concepts we mean some constituents of our thinking which would be some things in our heads. As said, I think that words like ‘bachelors’, ‘chairs’, ‘books’ and so on, refer to multitudes of things which are part of certain (and real at that) phenomenon in the world – a phenomenon of which we are aware. (I don’t think that concepts are Platonic ideas neither.)
I would also take externalist position on words meanings also, as I think they only have meaning in the context of language as part of the practices in the society, so again, would take externalist stance on this also.
So, I guess there is some kind of tension between those views. A very interesting dialectic here.