If there is a logical or epistemic barrier between the mind and nature, it not only prevents us from seeing out, it also blocks a view from the outside in.
I worry that the closest I come to staying in touch with the real world is eating bits of it: the epistemology of food, so to speak.
The ‘epistemic barrier’ is a thing between the mind and the external world: the thing that makes it possible to say that we do not have any knowledge.2 It’s not very popular: there are dozens of arguments for why it isn’t there. (You can tell they didn’t work, because there are dozens of them and not one.)
Still, I (and the whole field) learned a lot about epistemology arguing about this stuff, and the thought still tickles me.3 So here’s what I think Pearce was getting at:
- The brain is made of food, ingested matter.
- Knowledge inheres in the brain.1
- So knowledge inheres in (metabolised) food.
- Food, like all matter, is of the external world.
- So the mind inheres in the external world.
- So there is no metaphysical barrier between mind and world.
- So there is no puzzle about the possibility of knowledge.
Clearly this does not defeat the radical sceptic in her original, Cartesian internalist problematic (“it’s an epistemic barrier, not a metaphysical one - I don’t grant (1) or (2) or (4)”). But one good candidate for a philosophical fact is: nothing can. The only way to win is not to play.
- Maybe not just in the brain, but that doesn't hurt the argument.
- In the sophisticated Pyrrhonian form, "...not even of this sceptical proposition".
I don’t think I’m a brain in a vat. But I’m vaguely annoyed by knowing that an actual brain in a vat would think exactly the same thing for the same reason.
― Scott Alexander