The Strange Belief in an Unknowable "External World" (A Mere Lawyer's Take)
I'm confused. I would've sworn in another conversation we had that you thought the idea was useful.
I currently re-reading Cudworth, a persecutor to Kant, who stated a similar doctrine almost 100 years before the Critique was published. It's very interesting.
He say that of these things themselves, we feel only motion - effects the objects induce in us, specifically to creatures like us, that we then attribute all this richness we take for granted. The idea being there was something here prior to us existing, but it cannot be defined using the concepts we apply to nature.
But there's also Schopenhauer, who says that the-thing-in-itself is will, energy, the same thing you feel when you move your arm is what it would be like to be anything else in the universe, if it were conscious.
So there's no need to say that things in themselves are
completely, 100% unknowable. Perceiving effects, feeling as a subject and object or using the idea as a limiting notion, so as to not postulate a relational ontology ad infinitum, are useful and have content, to me anyway.
So it depends on how you take these ideas. I would agree, if we can know nothing at all about it, then the idea is not too useful.